Bolter Rush,
The difficulty of actually bolting the pump to the block would be determined by the lobe position on the camshaft. I think it would be accurate to say that even with the cam at the "heel", it takes some mashing and pushing to get the pump shoved up against the block to insert the bolts.
There is no priming procedure. This is a straightforward R&R. You sound quite knowledgeable so I am sure you will triumph soon.
Stuart
