After several days of reading and planning, I recabled my Denon D5000 headphones this weekend. For those interested, here is a step by step of how I did it.
 
Before I begin, I must give credit to these threads (here, here and here) that helped me prepare for the job. I hope my efforts can consolidate and fill in some gaps.
 
First off, here is the finished product:

 
I've had my Lawton Audio-modded D5000 for several years. Wire was from Double Helix Cables; I ultimately ordered the black Nucleotide (which is really more of a dark brown). Despite the warnings and high cost-to-benefit ratio, I got the Viablue SC2 Y-splitter and smaller T6s 3.5mm plug. Please note the entry and exit diameters. They have a huge influence on what you can or can't do in terms of sleeving and heatshrinking.
 
WIRE PREP:
Wire arrived Saturday, and I sat down to cut and braid the stuff. My main goal for this recable was to shorten the ridiculously long 10ft stock cable. I planned for a 5ft cable and ordered 20ft of wire. I actually received something closer to 25ft (which was nice of DHC). Unfortunately, I didn't take note of this before I started cutting four 5ft pieces.
 
Jumping ahead, my planned 5ft cable ended up actually 4' 2" from headphone entry to plug. I lost a couple of inches to braiding and 5-6 inches to the knot and loop inside of the earcups. This is fine for my uses, but I wish even more that I had noted the extra 5ft of cable that arrived. Oh well...
 
WIRE BRAIDING:
I'm a guy. An only child with no sisters. And my daughter's hair is too short to braid. Needless to say, I was lost with the braiding. I found instructions about the Litz braid and practiced earlier with some spare wire. When it came to the real thing, I carefully labeled each wire with color-coded tape (L/R positive and L/R ground) and numbers (1 2 3 4). I confidently sat down and then spent 30 minutes frustrating myself.
 
Eventually I stumbled upon the solution below. It wasn't enough to know which wire to put over which wire(s), my problem was making sure the wires had a place to rest in between motions. My janky lane method made this SO much easier.

 
I still had the color-coded and numbered tape on BOTH ends of the wires (Blue 1 = left positive, Green 2 = left ground, Green 3 = right ground, Red 4 = right postive). One end of the wires was secured a piece of shrinkwrap and a vice, and the other ends dangled off my dining table, separated by three dividers. Here is the braid sequence for those that don't know:
 
1 2 3 4   (start)
2 1 3 4
2 4 1 3
4 2 1 3
4 3 2 1
 
At this point, repeat the same motions you did above, but disregard the numbers:
 
Far left -> 2nd lane
2nd lane -> Far left
Far right -> 2nd lane
2nd and third lanes slide over to right (lanes 3 and 4)
 
At a certain point you may want to stop and take a break or tighten the braid. I would repeat the process until I ended with the original 1 2 3 4 (blue, green, green, red) order. Tape down the wires and do what you need to do.
 
Y-SPLIT:
Keep braiding and tightening until you're left with 18 to 20 inches of wire (more or less depending on where you want your Y-split. Do keep in mind that you will need ~6in to go into the earcups.
 
Borrowing from a trick this thread, I slipped on a slitted piece of shrink wrap (obviously keep L/R wires together):

 
I really wanted the Y-split heatshrinks to be hidden inside of the Viablue casing, so the total length of the shrink wrap pieces had to be shorter or the length of the case.
 
I then twisted the pairs. Following the suggestion from my research, I carefully counted out 34 twists each, pinned them and made sure they didn't twist out.

 
Stupid thing about this plan was that once I decided I was going to sleeve the pairs, the careful twisting went to poop. This is not to say you shouldn't still twist the pairs prior to sleeving, but I won't sweat the details the next time.
 
Sleeved the pairs in 1/8" nylon multifilament (measure length from the Y-split up to about 3-4 inches from the paired ends). The process is slow going. You have to pinch and push the sleeve toward the Y-split and then pinch again. Then smooth the cable out. Think of it as an earthworm, compressing and extending. Eventually you'll get there.
 
A few notes: You will want to cut the nylon with a hot knife, or use a SHARP pair of scissors and then LIGHTLY seal the ends with a heatgun. You do NOT want to have a frayed mess. And let me say that the $15 heatgun (it's not gun-shaped, it's cylindrical) that I got from Fry's last week was the BEST purchase, and I could not have done this job without it.
 
Add two short pieces of heatshrink to hold the nylon at the split. Again note the total length of shrink:


I doubled up the single short piece of shrink with another piece, and then encased the whole thing in a long piece. I think I added one more long layer, followed by 1 or 2 short layers on the end that would meet the gold hex screws Here is the finished product, prior to Viablue closure.

 
EARCUPS:
Remove one of the earpads by twisting the base counter-clockwise. The puffy pad will spin all day, so you have to grab the base before rotating. My pads are much puffier due to the Lawton Audio mods.
 
Undo the four screws that hold the wood cup and driver to the frame. Note that these are flat-headed screws, while the next four are round-headed. Remove these screws to separate wood from driver.
 
I chose to do one of these at a time because I liked having the security of the other cup to reference should I have gotten confused. Also, it helped me to work on LEFT and RIGHT separately.

Upon separation of the driver, you will see two wires soldered to a board. Note that one of the sides has a red mark (and either a red or white wire going to it). This is the positive contact and you will solder your left or right POSITIVE wire to it. You will solder the ground to the other contact.
 
But first, I put one drop of flux to each contact, hit it with a 600-degree iron (Hakko 888) and each wire popped right off. I then went back and removed the extra solder from the driver contact with a solder sucker and iron. As noted by others, don't burn the driver by leaving the iron on too long. Take your time and use the right tools. I do not assume responsibility if you mess up your Denons.
 
Undo the knot and remove the stock wire. Replace with your paired cables (keep in mind LEFT and RIGHT!!). Tie a knot with your cable to match the location of the stock. I followed it up with a zip tie on the bare wire side of the nylon. The other how-to thread put a zip tie on the other side. My placement made more sense to me, but you'll notice that stock cable didn't even have one.
 
Solder positive wire to red-marked contact. Ground to the other contact. This is how mine looked (despite the photo, my joints are small and shiny); note that the metallic insulation and glue is from the markl mod.

 
Line up the wood cup so the corresponding screw holes line up. Make sure the silkscreened "Denon" is roughly perpendicular to the cable exit (it's about 10-degrees rotated). Screw in rounded head screws. Pull the excess cable through the exit and line up the driver+wood. Note the notches in the wood that line up with the swivel pivots on the headband ring. Make sure that "Denon" is in the right position again. Screw in flat-headed screws.
 
Repeat the same procedure with the other cup.
 
Key note: Make sure the cable lengths are the same from Y-split to earcup. Adjust the position of the cable knot to shorten or lengthen the cable.
 
[That's it for now. I'm exhausted and will post the 2nd part of these instructions tomorrow.]

Back again...
 
Once the earcups have been reassembled, it's time to turn attention to the 3.5mm plug. And it takes A LOT of attention!
 
3.5mm PLUG:
It's been said many times that the Viablue 3.5mm plug is a pain to assemble. Despite these warnings, I really wanted to match the Y-splitter and liked the tiny footprint of the small 3.5mm plug. Comparing to how easy it was to assemble Switchcraft 3.5mm plugs (right-angle and straight), I don't think I would choose the Viablue again. 
 
It must also be said that the SMALL Viablue plug has a very small barrel opening. It is big enough to to hold the 4 strands of Nucleotide wire and two layers of shrinkwrap. Had I decided to sleeve the 4-braid, I would have to had to make sure it would have all fit the Viablue barrel.
 
Things to note in pic below:

1. Plug contacts tinned. Ground wires twisted and tinned.
2. Left wire tinned. Following a suggestion from Zynsonix, I slid a piece of shrinkwrap on the left wire that would eventually be slid onto the contact, providing a buffer from the right and ground. However, the piece of shrink I used shrunk when I soldered the wire and eventually had to be cut off. Oh well... Good idea, next time I'll use a larger shrink.
3. Note the plastic spacer (comes with Viablue plug) is slipped on; but this will eventually get cut off when I had to change my gameplan).
4. The barrel of the plug (not shown) is already slipped on as well. 

 
Things to note in next pic, which I call my "mistake photo":

1. I started soldering ground wires first. This was pretty easy.
2. Next I soldered the left to the center post. This was a little tougher.
3. Once those were done, I snipped, stripped and tinned the right wire. Soldering this one was nearly impossible. I have a pretty steady hand, but the wire kept slipping off or I'd glob a bunch of solder or a gap could be seen. I literally spent 30 minutes trying, soldering, desoldering and trying again.
4. I melted the plastic "post" a bit as a result. Ugly, but inconsequential.
5. Because I stripped so little of the insulation off, the soldering heated the insulation a bit (note the half "barbell")
6. Finally, I triple and quadruple checked that my joints were not in any danger of touching each other, since I didn't have that Zynsonix-suggested buffer shrink.
7. Joints are shiny, but right and left have little peaks that I'm not thrilled about. My attempt to smooth right wire peak would just pop off the wire. Definitely not my best work.

 
Next came some improvisation on my part.

1. The shrinkwrap seen above (below the blue rubberband) was too far away from the plug. When the spacer and barrel were slid up, there was a gap between plug and shrink.
2. So I cut the old shrink, and slid on a longer piece, up to the gold ground plate. A second shorter piece was cut to sit flush with bottom of barrel and applied.
3. I had to snip and remove the plastic spacer.

 
NET TAKEAWAY: Were I to do this whole process again with the Viablue, I think I would have just taped the four wires together before braiding (strong enough to hold the braid end). Then braided and soldered on the tip. Then removed the tape and added the two pieces of shrink wrap shown above.
 
After sliding on and screwing in the barrel, here is the finished product! It sounds great, and I'm proud of the work. I hope this guide is helpful to the next group of intrepid souls. Good luck!
 

 

 

now I want to buy that cable but I don't have any money... and replacing the cable on my k550s will likely be a PITA.

mchang,
 
I have been scouring the net, looking at the different options I have when replacing the stock cable on my markl modded D2000's, and found yours to be the most comprehensive write-up. thankyou.
 
I almost went as far as ordering black nucleotide cable, but was put off by the ridiculous postages costs to the UK.  I ended up going for this stuff from toxic cables, who have a great reputation.
 
The only question I have (bearing in mind I'm a novice) is what benefit is there in braiding/weaving the cable? I plan on sleeving the whole cable, so is there any point braiding? Does it improve the durability/sound quality or is it (as I suspect) just aesthetics?

Sorry for the late response, herrbbiiee. Didn't see new post notification. And thank you for the kudos.
 
From what I've read, braiding the cable helps shield against RF interference. I've posted a question to the DIY Forum for a few more specifics on this phenomenon, but no one has replied yet.
 
So it appears to be one of those "do it because everyone else thinks it does something" tasks.