Here is the tool that I used to install the pulley end seal:
This is a pvc thick wall coupler using a threaded rod and one of the motor mount washers. Both front and rear seals press in easily, but I have had the seal spring pop off before because I seated a seal by hammering it into place. Also, you run the risk of cutting the rubber on the seal. Using the tools may be a classic case of overkill, but is easier than having to pull the engine back out to deal with a leaky seal!