I had one where the wire that connects the releases was broken and the seat was all the way back. Had to grab ahold of the wire w/ visegrips & pull on that while pulling the lever as well while I was sitting in the seat looking like a dog humping a couch cushion. Got it far enough forward to get to the rear bolts, though.
For the rear seat belt bolts, I worked them for a week or so. I'd hit them with Free-All, let them sit overnight, and try to move them a little further each time. Finally got tired of it and used my air impact wrench. They came right out with no issues. Can't say it would be that way every time, though.