After pulling the hub bodies, the outer bearing should fall right out.  The inner bearing will need the seal pulled, in order for the inner bearing to come out.  Best thing to do at this point is to degrease the inner hub body.  Get it all clean so you can see the races and the backsides of them.  Then like Prismo said, use a punch to knock out the races.  There is two notches on the inside of where the race seats up against, these are to help remove them.  Then carefully tap in the new races with a brass drift punch.  And don't get in a hurry, cause the race won't go in straight if you get careless.  Need to be slow and steady and work your way around the race. 

Then pack your inner bearing and put it in place.  Then carefully install the seal.  Seen many guys forget the seal cause they get in a hurry.