Did mine this Easter weekend, did it in half expected time, thanks to your excellent diy, Thanks! Two points I did, one, is that the 6mm tapped holes for the push-out bolts were rot, and next to impossible to use. So, I put in two short 6mm bolts, with lock washers, in the new pump to protect the holes for future removal. They must be short, so as not to come out proud of the mating surface.
The other thing, I have done this several times, each with success, put the car front up on some fairly steep ramps, so as to put the rad up high. Follow the instructions for filling, but put the water in very slowly. The first time I started the engine, I got a fountain out of the bleed in no time!!