Some people would argue about leaving the races in.
I removed & repaced the races the last time I changed the bearings. Only because it's so easy & I have the proper tools.
I used a metal punch to get them started then used a brass drift to get them out the rest of the way. You must use brass so you don't mess up the hub.
Then use a seal driver to set the new seal.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=547
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93424
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=95853
I got a nice heavy brass drift from Harbor Freight but I can't find it on line.
Danny