Changing rear springs

Basically a floor jack and jackstands.
Raise the rear of the car with jack, put jackstands under the frame, lower the rearend, there should be enough room to get the springs out. If not you may need to disconnect the shocks to get a little more room. Very easy job, 30 minutes or so.
There are some rubber isolaters on the top side of the springs, sometimes they will stay stuck to the car, sometimes they come out with the spring. Either way, make sure they are in when installing the springs back in.
take the lower bolts out of the rear shocks and they should come right out,30 minute job,just jack the car up and put the jack stands under the frame rails
You may also have to disconnect the upper control arms from the rearend to let it hang down farther. I had to do that on mine but I think it depends on what kind of springs you're taking out and putting in....still an easy job though.
With lowering springs it will be easier, they are usually shorter than the stock springs which will give you a little more room to work with.