So, I have an 02 wagon that is occasionally making rubbing noises in the rear. I am assuming that the bearings are worn. My question is how hard would it be to replace them myself? Also, should I replace just the rears or all of them?
You can do them one at a time. Doing it yourself requires a press and is a major operation. You have to remove the hub to put it on the press. The Subaru Dealers have a tool to do it on the car, and therefore may actually be the cheapest route.