Any help on crank pulley removal?!?

[Mart]

I would try getting a piece of plate about 1/2" thick and tapping a 1/2" unf thread in it. I'd turn it down until it fitted just inside the pulley and weld it to the remnants. The weld would be only at the very end of the pulley. I'd then take a 1/2" bolt and shape the end with a shallow taper like a drill and use it to (hopefully) wind the pulley remnants off.
If you weld lower down the length it will make the part tighter due to shrinkage. this assumes the 1/2" bolt will pass down inside the 5/8" thread already there.

It might be worth just grinding the diameter down but only adjacent to the keyway. Stop grinding when you get to the key. It might then move off easily or use the method above to pull it off. Weakening it first would help I would think.

Mart.