How do I pull a drive belt pully off the crankshaft for a white garden tractor gt2550. I NEED TO GET TO THE PISTONS TO CHECK the rings, and I don't want to put a pully on it for fear off messing up the pully.

They very seldom come off with out messing up.
.you might try spraying some pb blaster on it and let sit.
If you had a torch you could heat it up and maybe get it off.
I usually plan on replacing it when I take one apart.
Luck