I would go down to your local hardware and buy a propane torch. It would work fine for heating the area to break that bolt free.
From your description, I assume it's rusted into the hole thru the spindle. A little bit of heat around the hole will help release it - it doesn't need to get red hot. If you can access the head of the bolt with a socket, use a breaker bar and start working it back and forth. Avoid hammering on the threaded end of the bolt or you'll mushroom it and you'll then need to cut the mushroomed end off. The largest hammer you can find is the best thing to use. Hitting it with dinky hammer is more likely to damage things.
Heat, PB, hammer, and repeat as necessary. It'll eventually come out.
