It can be done.

If it isn't stripped too badly, you can usually just run a tap through from the inside of the crankarm and clean up the threads enough to make it work.

If it's completely stripped, you can drill an oversized hole in the crankarm, tap a thread and install a threaded insert bushing. That requires some uncommon tools so it might be a cost prohibitive thing to do just once and it requires quite a bit of work so it might not be worthwhile to pay somebody else to do it for you.