You are right, the point is to help Shavedog. Dog, you have some form of information, hope it helps. It never was about RIGHT or ONLY WAY, initially was "give me information." Besides, my bladder is empty.
your best bet (and how I did mine) was take a spare wheel with you to the machine shop to have them bore out the GM wheels. I did it with a set of 17" denalis about 5 years ago. dude did perfect job on machining the centers out. they never gave me any troubles.