Pull the axle out and remove the carrier, or leave it on if you want to. If you dont care about the existing bearings, hit em out with a hammer and a socket..doesn';t matter what size... When you put the new ones in, MAKE SURE THE SPACER IS IN THE MIDDLE, or else you'll just end up ruining those bearings and more...Make sure to grease every part (Spacer, Bearings, Seals) Then get a socket, i dont know what size it is, but its pretty big obviously, just make sure its on the outside lip on the bearing, not the middle ring...then hammer those bad boys in.. Or if you have a press thats even better.. Oh, and make sure you put the Seals in the right way ...And while your at it, get a clymer manual... it tells you how to do everything..
Eric