[chicochapman]

I've no particular experience of this but try..............




1.insert a thin bladed flat screwdriver between the nut and the liner and push in hard to press it against the bolt.This might hold the bolt just enough to turn the nut.
2.Split the nut by cutting into it with a Dremel (other small rotary tools are available)
3.Grind the nut away with a grindstone in your drill
4. if the end of the bolt is proud of the nut, cut a slot in it so you can hold it with a screwdriver.
5. if not, drill into the end of the bolt and hope the "bite" of the drill bit will hold against the spanner.