BEFORE you pull the FW.
Center punch to marks. One on the FW down in the bolt area. Then another one right next to the first one on the crankshaft itself.
This way you don't have any chance of loosen balance.
You may need to take it to a machine shop to remove that busted bolt head.
Did the b'head twist off at the surface, or did it break below the surface??
What bolts are you using?? They need to be at least grade 5 certified.
Just lay the FW on your chest and roll out with it. The hard part is put'n that sucker back in and keep'n ALL of you fingers