Well from my understanding is you undo the control arm and get the springs out that way. the shocks do not need to be removed I believe.
Do a search on Sping Installation and see what you come up with.
I tried a spring compressor on my car, and it could not compress the spring enough to get it out. I just left it up to my mechanic, who is only charging me $160 to install all 4 springs.
'92 300CE - Sold
2004 C240 - C7 Wheels
2015 ML350 - P1, Pano, Ash poplar wood, Sport Dinamica interior, Running Boards Keyless go.