This is my "driveway mechanic" method of changing REAR spring/shocks on my 16V.
The first time I changed the springs, I was sure that I needed the MB-style spring compressors. So I bought a set from our friends here at mercedes Shop. During the process of removing/installing springs, I happened upon a method that, for me, was simpler than using the spring compressors to remove the rear springs (the compressors can be tricky to use).
I now access my springs by first jacking up the rear of the car using a hydraulic floor jack and resting the rear on suitable jack stands. I then remove the approprate wheel. I then, after removing the plastic cover and directly beneath the spring seat (there is a corresponding flat spot) just barely support the lower suspension element (i.e., the element which supports the spring -- i don't know the name of the part) with the hydraulic jack. With the suspension member supported, I remove the bolt which attaches this suspension member to the car frame (toward the mid-line of the car in the direction of the other rear wheel). Once the bolt has been undone and removed, the force of the spring on that suspension element is now being transmitted to the hydraulic jack. Very slowly lowering the jack reduces the spring compression. The spring expands and, evently, will not be compressed at all. On my 16V, I can then pull the suspension element down a little more and just pluck the fully expanded spring out by hand.
I like this method since I never have to hold a fully compressed spring in my hand (which unfailingly makes me very nervous) either to remove it, unpress it, or reinstall it.
Installation is essential the reverse. The only tricky part is lining up the hole on the part of the suspension element that receives the bolt to the carrier on the car frame. This can take a little practice -- to get the holes to line up -- but in my experience it has been easier than reinstalling the compressed spring. Also, the locking nut on the bolt must be renewed.
Some of the more serious techs out there will probably tell you not to do it this way, but it works for me.