On the front end, the struts are the only limit stops for the front springs. If you remove the struts with the weight off the wheels, the springs will fully extend, probably flying off their mounts at the same time.

On the rear end, the shocks also serve as limit stops, but you can unbolt the shocks and the sway bar link will keep the springs from fully extending.

At any rate, the rear shocks are way easier than the front struts. I did this about a month or two ago, and posted my experience here:

W124 sedan rear shock procedure

You'll need a floor jack, jackstands, ratchet and breaker bar, 17mm wrench, 17 and 10mm sockets.