Bit of a scare earlier when the HD250 Linear I's sounded like they had a blown channel after clearing out foam bits and putting the ear pads on. Faint output on one side and crackly. Luckily, after taking them apart and putting them back together, these now work normally. Of course, I tested impedance per side, and also tested output once the driver was removed, where I found that it worked fine while removed. No idea what happened or what may have shifted with the ear pad work or cleaning. Obviously, be careful when cleaning out foam around drivers.
So here's the rest of the details on disassembly, since I was unable to find anything specific in the way of posts, pictures, or videos related to disassembly.
To remove the drivers after removing ear pads (ear pads detailed in my prior post):
1. Optionally pop the driver housing (cup) off of the headband by just pulling straight out with sufficient force. It's simply a plastic ball socket deal. The rest is easier of course when the headband is out of the way.
2. Remove the silver ring by using fingernails to leverage it off. Thumbnail on the housing and index or other nail on the ring is what I found to work best for me. You'll have to unsnap it by working around the perimeter after the first area starts to separate (may pop loose). You or your S.O. may break some nails in the process. Mostly kidding... it wasn't assembled by Hercules and they aren't glued in from factory.
3. Remove the plastic driver holder/surround assy from housing (cup) in similar fashion by using fingernails. Don't worry about the driver, wiring, or any other major parts coming loose - they're all together in the assembly. Maybe you could do this without removing the metal ring first but no idea. There's just a small black plastic doodad at the back end which will be separate and another felt disc once driver assembly separates from the main housing.
Wish I would have taken pictures but was in a frenzy to determine whether this pair was shot. There wasn't any foam behind the drivers on mine to go bad, just the felt type of ring similar to what's on the front side. So I don't see much reason to remove the drivers unless you have a similar problem or have to swap drivers. If you use a can of keyboard duster or similar light air pressure, you should be able to carefully blow out any degraded foam from around the front side without worrying about disassembly. I had quite a bit of degraded foam and didn't notice any remaining in the back after cleaning these earlier without pulling drivers off.
There's also no point in taking the badge off the outside of the housing unless yours are loose. If so, you may want to glue them down while disassembled. They have a couple of metal pins that are bent over on the back side to keep them in place. One of mine was slightly loose so I tried futzing with that thinking there may be a screw or something behind them early on. Nope. Anyway, it won't be loose anymore.
