Anyone know how to remove a locking wheel nut that has sheared

 

try wellding a socket to it

 

+1 for welding on a socket or if thats not possible ( no welder or no welding mates ) a cold chisel and a hammer usually will work

Slightly slacken the other nuts 1st, jack up the car ( this relieves the load from the nut as much as possible ) then using the cold chisel & a decent hammer create a ridge at the outer edge of the nut, preferably with one solid ( hard as possible ) hit this hit is straight into the nut to create something for the cold chisel to dig into when you next tip the chisel to around 45 degrees hit again to turn the nut counterclockwise obviously !

Ive done this many times but usually cause either myself of my "mates" loose the nut key

Good luck, but its not really a massive or difficult job, usually these locking nuts are not tightened nearly as much as a normal one

SS

 

Try this http://www.uktools.com/17mm-buster-pitch-p-9279.html