back off the nut on top of the flywheel so you hit that and not the crankshaft. Get a medium to large screwdriver or small pry bar. Lift up under the flywheel pretty hard, then rap the nut with a hammer. It should pop up in about 3-4 hits.

Happens pretty often, don't feel bad. That and the crud in the bowl of the carb are probably the 2 biggest issues with small motors.