Leaking hub

Changed my wheels over today and realised that my n/s rear hub is leaking transmission fluid, this is running onto the disc, which can't be great!

Can somebody advise what I need to sort this out? Can I just replace a seal or is it the whole hub that needs changing?

If I need a hub, is it a DIY job or is there pressing involved? Will the diff need to be drained & refilled?

Anybody used these parts? LAND ROVER DISCOVERY 2 TD5 & V8 REAR HUB AND ABS SENSOR TAY100050 | eBay

Thanks

I have just done my near side rear for the same reason.fairly straight forward job.my hub came apart as the puller drew it of the shaft.lucky i had a spare hub.more likely hub than seal.you will need a 1"1/4 socket a mahoosive torque wrench.about an hour and a half.

Same here, The hub bearings themselves let go, not the hub-to-axle-casing o-ring seal:-
http://www.landyzone.co.uk/lz/f8/rear-hub-warranty-issue-244468.html