Take the brake drum (or disc) off, then remove the 5 nuts holding the bearing retainer to the end of the axle housing. Remove the bearing retainer and the axle with the bearing will slide out. Be careful not to damage the grease seal(s). Usually now is a good time to examine the bearings, replace the grease seals, and replace the bearing retainer gaskets.
You will need a hydraulic press and some sort of fixture to press the studs out. Any decent automotive machine shop should have a large press set up for this. Also get the new studs pressed in at this time. Don't hammer the studs out, you'll probably just bend the axle flanges.
