crankshaft hub on cavalier

I have a 1994 cavalier with 2.2liter 4 cyl engine and the timing chain is broken and i'm needing some tips on how to get the crankshaft hub off. I been trying to get it with a harmonic balancer puller, but i can't get it to come off. Does anyone know a trick or two as to how i can get this thing off. Do i need to tap with hammer as i'm turning the puller or what? If anyone knows anything that may help me with this i'd appreciate your input.:banghead: