The Bentley manual probably covers it, but from what I've heard it's pretty easy. Don't even need to jack it up or pull the wheels. The bottom of the shock attaches to the wheel carrier with one bolt, and the top of it attaches to the body, somewhere behind the rear seat. You'll have to poke around a bit to find the mount, but it looks to be just a single nut at the top.
Here's a pic of a subframe from an eBay auction that shows the shock attachment point, but not where it attaches to the body.
The design is pretty similar to the e38 & e39, so if you can find videos on them it might be of some help.