For years I tried to find the best way to remove a crank with stripped threads, then one day I discovered the answer. If you have access to an air compressor, go to Home Depot and buy a $20 air hammer. One short blast to the backside of the crank arm with the blunt tip that should come with the tool and the arm will fly off with very little damage. Simple, easy and cheap.
North Rim Adventure Sport, Inc.
178 E. Second St.
Chico, CA 95928