1) Get next door neighbours wife on her knees wearing a bikini to do it.. while you sit in a deckchair sipping Cognac...
But if you mean "the best way to clean it yourself" then it's 'orrible grease. Use some degreaser or other solvent (kerosene, or white spirit would also do it) on a paper towel, so you can throw it away afterwards.
2) Remove the wheel, detach the hub from the suspension strut (you might also have to detach the track rod, but you should be able to leave the wishbone knuckle still attached) ...
Then remove the clip from the inner CV joint... push in the driveshaft so you can remove the threaded/outer end from the hub and then withdraw the inner shaft CV/spider from the cup.
Not sure why you'd want to change the whole driveshaft though, just because the outer CV boot is split.
3) Theoretically, once you have he driveshaft out, you can "remove" the outer CV from the shaft... but in reality it'll be stuck fast and you're likely to damage it by the amount of belting it will need.
You can try to approach it from the other end... remove the spider (held on with a circlip) then the inner CV boot and then feed an outer CV boot on from that end.... but as above, you're likely to damage the inner CV/spider if it doesn't come off neatly... so buy a spare one, before you start, if you're going this route.
The easiest ("garage") option is to fit an elastic CV boot. These are like regular CV boots but instead of neoprene they are made from some elasticky rubber plastic ... If you have a "cone" you just hook it over the cone to stretch it and then while it's all stretched out, you just feed it over the CV joint and job done. Your local friendly garage would probably fit an elastic boot.
Bring them the whole car or just the driveshaft and get them to do it. It's a few quid if you dismantle the driveshaft yourself.
Ralf S.