Need help opening up Realistic PRO-60

I've got a set of Koss Optimus PRO-60 headphones. I've been researching replacement foam/cellulose to replace my old rotted out ones only to find that one of the channels died. You can open it up by removing/stretching the metal bracket off of the outer lip of the headphone. Then you press in each of the small 4 plastic clips that are just outside the inside of the large rectangular openings. Gently press in each of the pins as you separate the two pieces from each other, then once inside if you want to get to the drivers, there's another set of 4 plastic clip/pins that let you get into them. There's also a loose large cell foam piece that looks like a debris filter that can just fall out. Just tuck it back in behind the headphone cable when putting the phones back together. On my Pro 60s the bracket doesn't form a complete ring. I had some warped/distorted metal from prying so when putting the headphone bracket back just straighten and squeeze to get them back into shape as needed when you're done. Good luck!