Many of these leather work tools used in this video might be available at your local library.

I'd like to try crocheted cotton earpads sometime.

Hello, I made this tutorial once when i repaired my bose headphones : https://www.instructables.com/Bose-Headphones-Ear-Cushions-Replacement/

This is cool, and what great timing - I just spent the last half hour sewing up the seam inside the ear cups of my QC35s. The fake leather is flaking as well so I'll definitely try something like this in the future, probably with fabric (maybe a 4-way stretch cotton knit, athletic fabric probably a good choice)

I was also thinking about crocheting a cover for the top band.