Yes, just last week....................
I did it at work though, so I had a rattle gun to undo/do-up the drive flange nut - be prepared for pain if you haven't.........
simple enough job, prop nuts off, big nut on flange under where prop lives off, (with Hand-brake on), leave hand-brake on, undo 2 set-screws holding drum, take off drum after letting h/brake off - with wheels cocked, obviously, pull out flange, insert large screw-driver in seal and lever out, hammer new one in until flush all around, fitting is the reversal of removal, after cleaning up drum and shoes - taking the shoes off is best, but thats a whole other story.....
Have fun...........
Oh, errrr, you were asking how to do it, right?......
