Try to beat allen key deeper in, if that does work. You could try to go 1 size up on the allen key but would have to knock it in with a hammer and would need to replace bolt it after you got it out. finally if that does work you could get a set of easy outs and drive the correct size in to remove but would still need to replace bolt after. Been a diesel mechanic for 13 years so I've had my fair share of bolts/allens stripping..lolIm pretty disappointed right now. Stripped one of the hex bolts trying to take it off. Anyone know what i could do?