The break was a lot cleaner. I've been soaking with penetrating oil and tried using vice grips to slowly turn. All it's doing is spreading the bolt and the grips are brand new.

I ended up finding a local mechanic well experienced in this and he said he'd come by and take it out. At this point I would rather pay him $100 to remove the bolt instead of me learning on a perfectly good engine and making a far more expensive mistake.

I need to get my hands on some busted mowers and practice this extraction process a few times to get a feel for it before I feel comfortable attempting on my car. If I had done this before I probably wouldn't be so intimidated to have at it.