Anyways first things first, here is the supply list of everything I got. If you have a soldering iron you don't need a new one, just make sure it isn't above 45w and you will be fine. You will need new solder though. As for de-soldering equipment, don't waste your time with it for this.
Neutrik 3.5mm Right-Angle Plug Nickel/Nickel $2.69
Techflex 1/4" Nylon Multifilament Cable Sleeve $0.24 per foot
Heat Shrink 1/4" Tubing 4-Feet Black $2.32
Heat Shrink 1/16" Tubing 4-Feet Black $0.88
Elenco AmeriKit Learn to Solder Kit $13.02 with Prime free shipping
24 AWG Silver Teflon Wire Assortment 7 Strand 40-feet $7.95 with free shipping
Power Drill with small drill bits increasing up to 1/4"
A small flat-head and phillips-head screwdriver set
So that is basically all the tools you need. I provided links to the more hard to find items. I also showed you how much I paid for this complete project. The first 4 links were from markertek.com and the total shipping was around $5.15 and it took only 3 days to get here. I also broke one of the 3.5mm plugs and they were kind enough to ship out a new one. Excellent service. Also, for the Texhflex, I ordered 14 feet and it came as one long strand. I ordered only one or two of the heat-shrink tubing as they came each 4-feet which was plenty enough. As for the soldering kit, I recommend the Learn to Solder Kit from Amazon.com because it has a decent soldering iron and solder, and it provides a cool little project you can learn on. I suggest doing that before doing the headphones just for practice. As for the wire, I got it from DBVending on eBay. It was less than $8.00 with free shipping for 40-feet. Excellent customer service and wire.
On to the process of re-wiring the headphones.
1. Take apart the headphones just like in the soundstage mod process. Start by pulling off the ear padding.
2. After that, take off the outer mesh grill.
3. Next, take out the 3 tiny screws. These are pretty tiny, so you need a really tiny phillips-head screwdriver to get them out. Something similar to an eyeglass screwdriver, but just a little bigger. Also, set the tiny screws in a different place than the headphones so the magnet doesn't get them. Keep them secret, keep them safe.
4. The next part I will try to explain without pictures because it was hard to do the wiring plus take pictures with only 2 sets of hands at the time. I forgot my robotic extensions so I will do my best to explain how to do it. It is fairly simple. First, I took out the stock wiring completely. There is a metal clip inside the driver housing that you need to pry up with a flat-head screwdriver. It comes out easy so take your time and just nudge it out. You can see it through the hole in the second picture from me taking out the tiny screws. Go on the end that has the tab and pry it up. Keep that as the same place as the tiny screws. Now with that clip off, you can pull out the tiny jumper plugs on the end of the cable. They just pop right out like jumper pieces on a hard drive. When you get all four out, feed them through the hole and eventually they will come out. Now you have the old wire out. Next, you want to take a pair of wire clippers and clip the wires going from the driver to the little PCB board. There will be four of them all together so clip them close to the PCB board, doesn't need to be perfect. Also clip the wires going into the headband housing. Now you have all the driver wires out from the PCB Board. Next, take a small flat-head screwdriver again and pry underneath the little PCB board as well as the jumper pin housing. Pry a little at each side at a time if you want it in-tact for the future. It will eventually pop out, because it's only held on there by hot glue drops. Keep that someplace else. Now you have the PCB board, jumper pin housing, and old wiring out. The driver itself should come completely out now, so set that aside someplace away from the screws and everything.
5. This next part I took some pictures of for better reference. I will explain how to take out the old wiring from the right driver inside the headband. First off, you should take apart the right cup the same way I just explained on how to for the left cup. Cut the wiring as well from where the wire feeds through the headband, and set the right driver aside near the left driver. Now, back to the left cup, take out 2 phillips-head screws and a piece of plastic (Photos 1,2). You can do this for both sides, and keep the parts semi-near the other small screws. Just don't mix them up. I had a pile for each screw set for each side so I wouldn't mix them up. Now that the little piece is out, take a small flat-head screwdriver and pry off the ear cup itself where it attaches (Photo 3). Just be careful here to not scratch it and it should pry off easy, then you can pull it off with your hands. Set both cups aside near the screws for the joints we just took out. Now you will be left with just the headband with the little cord inside. On the headband itself is 3 screws (Photos 4,5,6). Take them out on each side simultaneously and set them aside. Now that little piece on the headband should pry right out when you put a small flat-head screwdriver in the hole where the wire was cut off. Once this little piece is off on both sides, just pull the wire from one side and it should come completely out. Now, put all those screws back on the headband piece, put the cup on just the left side of the headband, and those 2 tiny screws that hold the headband in place.
6. Now, you should be left with just the headband and the left cup attached. This next part I will show you how to drill for a dual-entry cable. I used small bits, eventually progressing up to 1/4" or the next size, which I cannot remember. Just go until you think it looks fine. For reference, I made a nice thread about it and the guy helped explain it very nicely to me and I have pictures there. Just follow this link: http://www.head-fi.org/forum/thread/511708/help-with-drilling-hole-for-dual-entry
After you are done with your drilling and are satisfied with the look, next comes wiring up the new wire. The hole doesn't have to look perfect on the inside, although you might want to polish up the outer side of it. The wire will cover most of the scuff marks if you made any.
7. Anyways, as for the new wiring, I cut off about a foot and a half of the techflex cable sleeve for the dual entry. Then I cut off about an inch of the 1/4" heat shrink tubing and placed that on it. Next, I unwrapped the new wiring. Then I took the one solid color for the signal wire, and a striped wired for the ground. I fed them through the techflex and had about a foot on the end I was going to solder to the drivers. Do this for both sides.
8. Next comes the soldering to the drivers themselves. It really is simple. Just heat up the solder that is holding the tiny wires in place, and pull them out once the solder gets hot enough. You will tell when it's hot enough because it will liquidify. Once both wires are out, set them aside or throw them out, whatever you did with the other tiny pieces of wire. I held on to as much as possible to sell, in case someone messed theirs up or wants the single sided entry instead. If you want to use your 1/16" heat shrink tubing, put it on before you start soldering the wires on and heat it on there. Use about 3 inches of it, and leave about an inch or so on the end you want to solder on the drivers. It fits perfectly on 2 of the 24 AWG wires, I just forgot to use it. It will make a much cleaner look inside the housing once your done. Now, solder each wire to the right contact. The ground wires each go to the small solder point nearest the center of the driver, while the signal wire goes to the opposite contact. Make triple sure that you remember which signal went to each driver. The grounds don't matter because they will be tied together, but you have to make sure which color went to each side of the headphone for the signal. After you got them soldered on, it should dry like instantly. I waited a few minutes just to be sure, then I pulled each foot and a half techflex that I got earlier into the openings. Pulled the heat shrink up to the ends. For the left driver, you can just re-use that little metal clip that held the old wire in place for tension. As for the right side driver, I used a very small zip-tie and fed it through one of the small metal clips that held the grill on. Then I just fed the end of the techflex into that tube and zip-tied it down. Then just get rid of the extra string from the zip-tie. Now, you should have both heat-shrink tubes through the holes. Grab your heat gun and shrink them in there so it makes them hard. They should stay in there very well. I just put like 1/4 into the hole, and the rest was outside of it. Once that is done, you can now grab the rest of your techflex. Put an inch or two of the 1/4" heat shrink on the end of one side. Next, cut it to the length you think you want it, including the already there top pieces. Now comes literally the second hardest part of this mod. Start feeding the ends of the wires through the techflex. It should go in there fairly well until you near the last 2-3 feet of where you want it to end. When that happens, very patiently, pinch the techflex, and push the wires down. After you do this a few times, like 10 per round, start feeding the cable through the other end. When it is hard to push through again, do the same thing on the other end. Keep doing this until you are finishing and all the wiring ends up at the end. Make sure to leave about 4-6" inches for the connector to attach. When it's all fed through, go back up to the heat shrink tube in the middle. Feed each side through the one techflex string. I used a screwdriver for one side, after getting one side in. Once they are in there, near the middle of the heat shrink tubing, grab your heat gun again and shrink that tube until it gets hard again. Don't touch it because it's very hot.
9. On the other end of the techflex, where you left about 4-6" inches, put 2 more inch heat shrink tubes on to it. Just put one tube on the inside about halfway as the other way. Now you want to attach the plug end of the connector on to you wiring and feed that up into where one heat shrink tube ends. Now, grab your pliers and hold on to the connector piece, make sure not to bend it, and slowly pull the heat shrink tube about halfway on to it. This is added security so the connector doesn't come apart.
8. Now, you should have all the wiring complete and ready to put on the connector (The worst part about this project). Look at my photos for reference on how to put the wires on. As for the plug itself, the ground wires should be soldered to the tip of the end, and each signal wire goes to each side. I highly recommend one of those cheap dual helping hand stands with magnifier for this part. I just used a paperclip setup to hold it in, but it kept falling, etc. You can do without a dual helping hands stand thing, but I just bought one for the future because it will make it so much easier.
Now, after reading my book, you should be finished. I tried to explain it in detail where I couldn't take pictures. Like I said in another post, if you don't feel comfortable doing this or you want to save some money on the soldering iron and other tools, ask me. I will do it for you for free. I can just keep whatever is left over from the shipping charges. You will have to pay shipping both ways, and pay for the parts. I can order the parts myself when I get paid. Then all you have to do is ship your headphones using a USPS flat-rate medium box, which should cost about $15.00 one way. It is going to be less than $15.00 to ship it, so I will keep whatever is left over as profit for the labor. So if you want this mod done by me, your looking at $30 shipping both ways, and $25.00 for parts. So if you send me $55.00 via money order/check, I can do this mod for you. That is a pretty good deal considering that is about how much I paid on my parts alone. I don't have paypal, sorry. If you have any questions at all, please feel free to PM me.