It looks pretty straight forward, remove the Tines remove the plate securing bolts remove plate off shaft, prise out seal,clean up, replace seal and cover, am I right?, :)
The real bummer is getting the replacement bits the right size.
I find with my machine it's simpler to just top up with a bit more oil.
What I intend to do is remove the seal and take it along to a company that supplies bearings and seals to industry, even today I went along to Halfords with my drive belts and came home with two replacements at half the . :)price
Change the oil seal on my Mountefield, had a good look round and even the bearings are in good shape, put it all back together with no leaks from the oil seal, :)