Ok, I was going to pull off my exhaust assembly but I couldn't get it unbolted as there's a nut or something that's inside the engine that just spins. What do I do?

 

Do you have a picture? That way we can see what you see? That way we can better help you.

 

I'll get one when I get home

 

The nut may be seized on the stud and it is all turning together. Should come on out and then you can remove the nut, loctite the stud, then reinstall it.
It's threaded for and inch or so in to the case so it will turn for what seems to be awhile.

 

not sure how to upload to post. But its in my album

 

Sorry I'm not sure how to post pics but they're on my album.

 

Yep, pics verify. You're just turning the whole stud since you have all of that rust/corrosion on the nut. I know it's a pain in the **** because of the lack of room to work in but you're almost there. Keep turning until they come all of the way out. Clean off the rust, soak with penetrating oil overnight, remove the nut, loctite the studs back in, anti-seize on the threads for the nut, and you're back in business.

 

Thanks!