Well, I just did this myself, and followed the instructions in the Clymer manual. Basically, it said to pack both seals with grease and press them in (make sure they are facing the right direction; on the CR both seal lips had to be facing away from eachother). I used a socket that was as big as the outside lips on both seals to press them in evenly and as far in as they would go, and they pretty much just slid right in. For the bearing, I used a socket to press it in as well, but needed to use a hammer on the socket to drive the bearing in. Just make sure you are not pressing the bearing on its inner ring, as that will damage the bearing. You also should probably grease the impeller shaft and twist it as you are inserting it to make sure it goes in smoothly and you don't damage the seals.
I think if you do a search for "water impeller" or "water seal" you will find more info on this topic. Good luck,
Jon