[diverdan]

Make a new tool-----watch it break-----make another -----see the nut round off------force a socket on the remaining metal-----see the danged thing round off some more........

DON"T try to drill around the perimeter as it takes time and there is no way to tell if you are through the nut and into the wheel.

DO get a 19mm bore saw for your drill and solve the problem in 3 to 5 minutes! You know when go through the nut as there is a small void where the nut is curved next to the stud. It should "pop" at this point. A very small chisel helps to remove the very small layer of material covering the threads.

I just went through the whole process and was only able to find a 20mm bore saw which also worked fine.

Good luck, Diverdan