bolts or studs out and rock them back and forth , turn the crank so the counterweight is out of the way . # 3 is the hardest , sometimes you can grab he center with visegrips to help wiggle it.

I can't even see how you could get a hammer in there and have it be helpful ?

I've always wondered if it's safe to drill and tap a cast iron main cap so one could use a slide hammer like you see alum caps ?