It takes a 2 9/16ths socket...
to get the axle nut off. Seal replacement is pretty straight forward. I chose the "clean up the old lining " route. Others will tell you to replace them.
The best thing about this is that you get to set the bearing "preload" yourself. The little "U-clip" that crushes into the nylock part of the nut is just the best method I have come across so far for this job.
Do yourself a favor and adjust the bearing on the non leaking side while you have all of the tools out. I can almost guarantee the oil leak is form a "loose" bearing setting. (Now if you got the brakes on fire while towing down hill, all bets are off on "loose" bearing adjustment. )