I did drill them by hand, but I used two right-angle guides for horizontal and vertical. I was happy with the results, but since I autocross almost every weekend in the summer, I end up performing about 100 times the wheel changes most cars see in their lifetime. I did the helicoil fix in 2010 and raced all season with them in 2011. I replaced both hubs last winter and figured that I wouldn't tempt fate.