If you are careful, you can drill it in place. Slop your drill bit, and the tap, in wheel bearing grease before starting. The grease will hold all the chips and prevent them from falling into the pump. And, with the o-ring sealing gasket, you are pretty safe to pull the pump to drill it on the bench if you want to. Mine has been off 3 or 4 times using the same original seal set, no leaks.
I like details. They say man is a very visual creature!
