Rear seal?
You have to use a flat head screw driver and hammer from the outside edge to crush in the stock one. I used a piece of pcv tube to hammer in the new one until it was completely seated.
There is a special installer which consists of, among other things, a tapered cone that bolts the the crank flange to guide the seal in place. I have borrowed that tool several times from the dealer. It has all the parts you need to properly center the front and rear covers. You can use something to work the seal onto the crank, just be careful not to gouge it or nick it. And although it will go against your desires, be sure the crank is completely clean and dry-no lube of any kind, and the seal should be dry as a bone too. That goes for the front and rear seals.
