The headband can be removed, but you have to cut the fabric shell of the headset to do it. There’s a pair of clips on each side of the headset holding the top and bottom halves together. If you cut the fabric over the seam, you can separate the halves and slide the headband attachment points out of the shell (after removing the 4 screws holding each in place).

It’s a shame you couldn’t do more with the headstrap. The ribbon cable in there is a prime point of failure for the headphones, particularly the ground line which wraps around the back of the head from one headphone to the other (rather than both being fed from the headset)