James,
To remove the seal and bearing carrier (there is a ball race behind the seal), remove the 6 setscrews, use 3 of them in the jacking holes and screw in evenly to pull the carrier out. The circlip retains the special lipped washer, take that out and remove the seal. If you want an original spec seal, contact Richard Banister in the UK. They are black seals as original and the lipped washer fits them.
cheers Richard