pic showing two bolts to remove:
Remove wheel,
Undo the two bolts shown, and unclip the brake line from the body mounts.
Should then be able to get a pry bar behind rear drive shaft and lever/pop out the drive shaft from the diff.
You should then have enough play on the shock/spring to pull wheel and drive shaft clear of the diff
Prise out old seal, clean all faces well, insert new seal squarely (tap around face gently with wooden drift until its home square).
carefully guide the driveshaft back into diff, make sure you dont damage new seal. its easier if you have someone else pulling on rear brake drum as you guide it in..struggled a bit on my own.
Bolt back brake line, and the two bolts you removed
Top up diff with some more oil..
jobs a..