Hi Andrew - I didn't do it myself, but my mate did outside my house with a trolly jack and 2 axle stands. Didn't seem too complicated to do, but then I wasn't the one on my back under the truck! Took about 15 minutes. The only issue was spinning the prop to get access to some of the nuts, as we only had two wheels off the ground at a time, plus the prop weighs a bit! My mate has said the main issue maybe getting the bearings off the spline, and replacing it...... There is a very good write up on here by Hippo, one of the first that come up when you search for VCU bearings.
As for cost, I've bought a single GKN bearing today for £48 as I chickened out of the cheaper options and couldn't afford (justify to wife) two. My mate hasn't quoted yet for labour.
What sort of noise you getting? Mine was a soft grinding rumbling sound that changed with speed and not engine. Sounded more front passenger side to me, so was surprised to find it was a the rear of the two bearings. Was relieved when it came off and sound was gone, it was clear from the bearing it was knackered - my worry was the more ££££ parts....