When I did mine I got the bits from a local hardware store- Started small and worked my way up. After I had what appeared to be a "tube" I took an old Allen wrench about 4-5mm and ground it into a pick of sorts and lightly tapped until I bent down a lip and it just unscrewed out. I got I tap and a thread follower from a matco tool guy- I ended up just using the thread follower to clean out the threads- Get a good drill that is SMALL to fit in tight space. Good luck!

1990 Black Monty LS Over 300K' 1993 Isuzu Rodeo LS 4x4 46k (yes only 46K!)1989 Honda Transalp 600 Africa twin,