From reading previous threads, it would appear that they provide an exchange service where they send you a pre-done wheel and you send them your old one (which they will sort and give to someone else).
How hard can it be...
I'm not trying to discredit the level of craftsmanship required, but I'd like to think I can measure and cut some material without much issue. After that it's just a case of stitching it... Okay, my stitching might not be perfectly spaced or in fancy patterns, but it should do the job.
Some would call it ignorance, but I'd like to go with optimistic confidence