I hate extractors. I've never had one work.

My all time favorite tool is a huge set of channel locks (about two feet long with jaws bigger than my fist). Especially for undoing small diameter stripped bolts or studs. You can apply tremendous leverage with them on any shaped surface. FWIW, I also hate vice grips (they always slip) except to hold things together for welding.

From your desription it sounds like you might not be able to use the persuaders (channel locks), I might suggest a cold chisel and small sledge to crack the bolts and then drive it out with pliers or an extractor socket.