Problem Removing Crankshaft Pully

98 Lumina 3.8: Does anyone have a good way to stop everything from turning so that the bolt on the crankshaft pully can be removed?

Thanks
Scott

An assistant with a big screwdriver/prybar in the flywheel teeth or clamp a pair of vice grips onto the flywheel and let them rest against the bell housing.

Impact wrench?