Taking an old stuck tire off a rim

I have a 72 CT 70. The rims that came with the bike are wrecked, rusted and damaged. I found two usable complete wheels and a new tire at a pawn shop. I unbolted the rim and one side just fell off. The other side is stuck to the rim. It appears there is a wire that runs through the tire bead. Since the tire is already torn up I tried cutting it off with a blade but I can't get through the wire. I'm thinking of trying wire cutters or my dremel..any suggestions? Thanks

I've had luck using a small propane tank to heat the rim. Keep the flame moving around the rim and A.) you won't even burn the paint and B.) you will begin to smell burning rubber and the tire will then separate from the rim.

The heat works unless the wheels are really rusty. I jig saw the tire in half and cut down as far as possable to the rim and then use the dreme; to cut the bead loose