i tried that with a slimline pry bar, and it slipped still. I have no idea how they got it on there in the first place. Beats me.
Your best bet on that shock but it to get a weld on it, the bolts probably cross threaded and that's why it's broken off the chassis, it will need a new new. You could try getting some locking pliers ( vice/mole grips) on it, don't try tightening it up it will just get more stuck.
Not sure what's next. Might get high tensile bolt, chop off head, weld in. No other way. Can't put it in from behind as there is no room. @zed if I weld it in am I an idiot? I will be welding g from the front so it can be cut out and replaced in the future. I will make sure it protrudes all the way to the back length wise anyway, so the support is there. Can't see any other option.
you could weld the nut to the front ,maybe on a plate (like seatbelt mount) ,grind the lip flat first ...
You can just put a normal nut on and tighten the bolt into it, it won't go anywhere, it's only captive because of the difficult access
