Well, I can explain how we did it with me new motor last year, but you have to have an extra cam stator kicking around. What I did was borrow a cam old cam stator from my engine builder that was modified to fit into a drill chuck (like a long bit)
We then filled the pan with oil, and spun the stator (which drives the pump) from a corded drill at about 500 rpm. You need an oil filter on also, obviously.
Worked like a charm!