You should be able to get an inexpensive battery terminal puller, or small gaer puller from Harbor Freight, or Auto Zone, or a place like that.

The use of heat makes it "pop" off much easier..(more easily? I ain't none too good at grammar)

If you really loaded it w/ fuel, I would think maybe it's the rod...perhaps bent it...I doubt the crank is broken? Unless you can feel grunching metal to broken metal as you try to turn it, I'd say it's prob. the rod.