924S Waterpump Bolts Sheared. Resources

8 Waterpump Bolts and 4 studs, length 45mm.
http://www.mcmaster.com/#93275a014/=2qgbbj
50 mm M6 Studs for waterpump

Extractor also necessary if you can't back the sheared studs or bolts out.
These I purchased from Harbor Freight.

Left Hand Twist Drills can also work with drills that can run in reverse to remove bolts.

If your radiator is in place, you will need to use a short drill or angle drill. I found one at Harbor Freight for $30 which was excellent. Link to Drill.

In one case, my extractor itself broke. This required a carbide "burr" (search on Amazon) to be used with the drill to remove the hardened steel insert. The process was time consuming and led to the problem of "enlarged bolt hole"

For bolt holes which are too enlarged, I use Stanley Helicoil, a tap kit to allow stainless inserts to thread into oversized holes. My Helicoil (only 1 needed) was for M8!
Clean and re-clean the gasket surface, and use a new gasket with your new waterpump. My replacement came from URO on Amazon.