THIS COULD BE A DESTRUCTIVE PROCESS! Do so at your own risk!
They're put together the same as some hearing protectors I once rebuilt. The padding is glued to the hard plastic. As these are supposed to be high quality headphones, I don't know if the glue seam will break apart or not. You might try placing them in the freezer overnight (or outside if it's colder than freezer) and see if the glue will become brittle. Be very careful, though, as the foam padding and PVC covering will also become brittle. Once cold, try taking a sharp pocket knife and see if you can work it under the padding. A razor blade or X-acto knife won't work.
On the hearing protectors, the plastic pins that held the earpiece to the head....band(?) broke. I had to get inside and use pop rivets (plus a couple parts I can't remember offhand) to re-attach the earpiece to the head band. Used those things for many years afterwards!! So if you choose to do this, look at the engineering and the components. Modify anything you can or want to now, then make the repairs so permanent that the headphones should never break on you again! ...That's what I do, anyhow.
...If the connections don't seem strong enough, then I would re-work them - make them stronger. Maybe use better wire or a better speaker or a better pot (for volume control).
You could also contact the company and see if they can tell you what kind of adhesive was used. Maybe there is something that can break down the adhesion, such as the vapors of a certain chemical. But again, that's getting pretty touchy! Most items nowdays are made to be disposable. Even though these cost over $100 new, I
suspect they aren't really meant for being opened up for repair.
