First off you will need some tools:
Jack, axle stand, wheel brace, 6mm hex key, 17mm spanner, a good half inch drive ratchet with a 17mm flat sided socket (left hand side of pic)

Fist off losen the wheel the jack one side at the rear up and then reve the wheel. Place an axle stand under the car incase of any problems.
Once you have done that the drive shaft needs to be removed from the hub(the diff end does not need to be disturbed).

Now you can get to the spring retaining bolts. Use the 17mm spanner and the 17mm socket to remove the nuts and bolts.


You can now slide the lowering blocks in and reasemble. Make sure you refix the shimes as they are there to reduce rubbing.

Well I must say even though I have loads of weight in the back and with the lowering blocks the front is sitting lower. It looks nice as it is now and I'm sure you guys will love it.
When fitting blocks over 1" thick you need to slacken the top arm bolt to allow it to move. Retighten once the blocks are tightened up.