This is what happened to my rear differential drain bolt this weekend.

Long story short, when I was trying to loosen it, I got my directions screwed up and tightned the bolt instead, and stripped it . The bolt kept turning and turning, in either direction, but didn't go anywhere.

Set of tools used to get it out: pipe for extra leverage, small chisel, wrench with 24mm nut, easy out (not so easy), BFH and the nut):


And the drill bit used to drill a hole for the easy out:


Another picture of the badly abused bolt:


After a lot of rounds with the easy-out coming out of the drilled hole, hammering and prying with the chisel, the bolt started to be loose enough to wiggle. I also figured out that hammering the easy-out into the hole helped a lot, and finally the bolt came out . Did a quick thread chasing wih the fill bolt and the threads in the diff housing seem to be fine. Now I just need to go to the dealer to get a new drain bolt tomorrow.