yeah i agree with big blue, it wasn't hard at all. Just some lube and a socket that is the same size as the outside of the seal and it goes right in.
on another note its not crank seals, they don't hold coolent out.
Another thing that it could be is the little o-ring that is on the metal pipe that your side case pops over. This goes bad before your water pump seal does, but when it goes bad it lets more coolent flow outside and on top of your cases rather than in your oil. If I were you check the oring first, then if it checks out allright go to the water pump seal.