The drive shaft oil seals are very easy to replace.
Remove the road wheel, the brake calliper, and the deDion ear along with the hub assembly. Withdraw the halfshaft (with the hub and deDion ear attached) then prize out the oilseal.
Tap in the new seal using a similarly sized socket (as a drift) and a mallet. Keep the seal as square as possible as it goes into the diff casing. Replace shaft, ear, calliper and road wheel and the jobs a good un'.
A friend and I replaced one of these in about an hour outside the ski chalet we were staying in whilst on tour.
ETA; a garage and second pair of hands are useful but certainly not essential. If you're capable of changing the oil on a car or fitting brake pads, then changing the diff oilseal is well within your gift.
Edited by - weeman on 27 Oct 2013 20:40:15