You can trim cat claws with your own finger nail clippers, get the vet to show you how much is safe to remove - you don't want to hit the nerve or cause bleeding. That will minimize the amount of scratching damage that can be done. You can also get a sisal or coconut mat (the kind of welcome mat you have outside your door) - cats love these because they're tough and they can really get "stuck into" them. I have one on a board attached to a wall so they can stretch and scratch at the same time.

Signature line > "You can't fix stupid"