You will need the following tools to convert a P125 into a Pentium III cooler:

• 1 screwdriver
• 1 4-40 tap
• 1 tap holder (optional but recommended)
• 1 drill bit for 4-40 tap
• 4 4-40 bolts
• 4 non-conductive washers

I rounded up everything I needed at the local Home Hardware (home of the handyman :-)). Total cost of tools: about $10. Well, the only thing I needed to buy were the bolts, washers, tap and drill bit. 

Please note: The above drawing is not scale so please don't use it as a template! John Bogush over at John Bogus Celeron OC Info came up with the first drawing of the hole layouts. I added in the L2 spacer part.

You will have to mount the P125 heatsink inverted on the Pentium III because the 2 top Pentium II mounting holes share the same space with the require 4-40 Pentium III holes. This creates a bit of a hassle because we will have to drill a few more holes to mount the fan cover back on.

Next page: Let's Do Some Drilling