Locking wheelnut removing sockets - they are a normal socket which has a reverse thread inside them, they screw onto your lock nut and bite into it to undo it - it knackers the lock nut but works a treat

i got a set

where are u? if close to Leeds i would happily come and get them off for you

OR you could go the ghetto route and :-
A) Whack a Socket just too small for the nut over the top, this will knacker the socket but could bite on just enough to remove it.

b) Weld an old nut on top of the lock nut, only a couple of spots

c) Hammer and Punch (if you have enough room)

failing that - u're screwed.