Changing passenger side drive shaft seal

I need to change the seal that sits on the outside edge of the gearbox that the drive shaft goes through as it's leaking! Any body have any hints or tips for changing it? Is it fairly straight forward? Thanks

look in my thread i change it 6 month back on my car
M.B gave me some tips, but really nothing to do.

just drain the box, take the upper bolts of the swivel hub assy out of the shock,and take out the dirveshaft.

screwdriver job to pull outh the seal and put all back together

here is the page
look at the bottom and go on next page

http://www.gtir-motorsport-club.com/t1499p75-french-rally-sunny-gtir