Here's a picture on how I got the last bolt off to remove the oil pan. It's not the prettiest job, but I got it out. Laying on your back isn't the best for doing this job. JUST TAKE YOUR TIME.

I cut out the bolt housing part of the transaxle. Only the bolt housing part. I also cut the socket down to give me more room to remove the bolt.

I didn't fill the gap back in with a sleeve. I guess you can do that, if you're worried about the bolt housing strength.