I pretty much destroy the mech seal to get it out. I use a pair of needle nose pliers and rip out the springed seal so I just have the piece of metal in plain site. I then use a pair of metal cutters and begin to hack the metal piece out by twisting the metal so the seal sort of shrinks onto itself. Once the seal is out I pop out the oil seal and use a comparable size socket to pop the old
bearing out.

When I install the new bearing (I grease the bearing outer race and case) I use a comparable size socket and press the bearing in till its flush with the case.For the water pump shaft oil seal I use a over size socket and press the seal in till flush with the case. Before I press in the mechanical seal in place. I grease the outer part of the seal and the case area. I then line up the mech seal and
press it in as much as I can with my thumb(not much). Once I know it is fairly level I put the pump shaft in.I use the old seal that was on the impeller and put the impeller on the shaft and hold the shaft with a flathead in the notch and tighten it down until it bottoms out. I then loosen it up and add some washers between the old seal and the impeller( to push the seal down further) i put the nut back on and tighten it down again until the outer metal part of the seal is flush with the case(make sure you do not tighten to much or you can break the black part of the seal and start all over again).Once that is done I install and grease the new seal for the impeller and press it in to the impeller and then I apply a liberal amount of grease to the mechanical seal and put it all together.