Sheared Spring Pin on Crankshaft Gear

Hi Members. I'm glad join your forum. Of course, I have a problem I need help with. I managed to shear off the Timing Advancer Locating Spring Pin on the crankshaft gear. The gear is a machined part of the crank, and therefore, not replaceable. Anybody have any ideas on how to remove what's left of the spring pin that's stuck inside the crank gear?

This happened because I was trying to rotate the engine with the 22mm nut that holds the pin in place. The Allen Head socket bolt was loose (by others) and hence, the pin sheared off. Next time I need to rotate the motor, where should I be rotating the motor from? Also, any thoughts on removing the Spring Pin? THANKS!