Do a search here and you will find some very helpful posts. I have changed out a couple. The first one was a nightmare. The second super easy. What makes it tough is the spring loaded pump lever engages with the push rod that drives it before the threads of the bolts engage.
Yes, rotate the engine until the push rod can be pushed up with your finger as high or as far as it will go. Then get yourself a ball end type Allen wrench as normal Allen's interfere with the pump case. If the pump is square to the case, and the lever is under the push rod, it will screw down very easily. Alternate tightening the bolts a few turns on each side to keep it square.
I cut off the Allen wrench so I could fit it into a socket and used my palm wratchet, torque wrench, and extensions. Again, you need the ball type Allen wrench to clear the pump case. You need one hand to hold the pump square and one to turn the bolts.
It isn't hard at all if you do these little things.