Drop the prop, get the circlips out (you will need a GOOD pair of circlip pliers), these will probably need a bit of encouragement, a pre-soak with WD40 or diesel or something would be a good idea.
A small screwdriver can be useful if you put it up against the edge of the clip and tap it with a hammer, once the circlip starts to spin it will come out no problem.
Once you have them all off take the shaft and sit 2 sides of the flange on two big pieces of wood - I used some logs, you can use a vice but it tends to dent the shaft up a bit... and batter the yoke, this will drive the caps out the top of the prop shaft, flip it and do the same for the other side, once you have the flange off you can put the exposed spider legs on the logs and batter the flange and drive the cups out...
Clean EVERYTHING up, use some wire and clean out the circlip groove etc and stuff LOTS of moly slip or something into the cups and fill the spider, even if its prefilled add another light coating of grease... put a cup into the prop and circlip it, then put the spider in and let it sit in the first cup, then you can put the other cup in and press it in with a vice and a socket thats just about the same size as the cup. If you need to tap them in a bit with a hammer, make sure you have the spider let in the cup, or else you risk knocking the roller bearings all over the place! Repeat for the flange...
Make sure it all runs smoothly and without any resistance - just a little resistance you would expect from the grease...
I would also recommend replacing the prop shaft nuts and bolts for the sake of a few quid...