although it is possible to change the bellows at either end, the new bellows has to be stretched over a large diameter. This can be done either by a special air-driven tool - or by a simple cone (there are videos on YouTube showing how to fit).
Craig replaced the CV boot after taking the shaft out. There is a clip that holds the joint to the shaft which had to be opened up and the CV joint just pulled off. This is a broken one but you can see the clip.
A new driveshaft is costly - refurbished drive shafts are catalogued to save some cost. If you lose any gearbox oil you will have to drain and add an exact amount as there is no level plug.