series 2a gear oil inside rear brake hub

hi guys i recently became the proud owner of a 63 series2 a friend said i should sign up here so heres my first question.
when bought it came with a brake issue pulling to the drivers side quiet bad,on inspection of the shoes etc i noticed the rear driver side had gear oil in around the hub
1.)is it much of a job to do the seal?
2.)could this be the cause of it pulling to the same side as the gear oil soaked shoes or more likely all the brakes need to be adjusted and bled?

1 yes, and cheap too. Order a new seal. flange gasket and box spanner. And a set of shoes.
2 possibly - driver's side may have been adjusted up to compensate for oily brakes.

I recently did this job and can confirm for an amateur its really easy as long as you have the right tools.

After replacing the seal I realised that my axle breather was blocked so I'd recommend putting a new one on, they are only cheap and takes 2 mins to replace. Before I realised it was blocked I got back from a journey one day and thought I'd remove the breather to clean any crud out. When I loosened it there was a pffffffft like opening a bottle of pop. Made me realise how much pressure can build up in there! Can easily cause your seal to pop oil into the drum or wheel.

I got confused setting up the endfloat after re-fitting the hub and bearings. I had some good advice on a thread a month or so back if you do a search.

My brakes pull but were much worse before adjusting them. Just jack up each wheel in turn and use the adjuster nut on the back of the drum. Make sure your turning the right way and get them so they are one click off binding. You can have them just binding a tiny bit on the rear whereas I was recommended to have them just off binding on the front. Obviously clean your drum out with degreaser first!

After a new breather and new seal I don't get any leaks from the hub now.