Here's how I do it on our W124 wagon and 500E:

a) order 3-liters for MB suspension fluid;
b) order a new filter (the suspension fluid dipstick screws into it);
c) order a new length of hose between the suspension fluid resevoir and pump if over 8-years old;
d) Gather up some tubing to fit the return pipe that fits on top of the suspension fluid resevoir and a container that holds approx. 2-liters;
e) get an assistant who weighs at least 125-lbs or can exert that same force;

1) Using a syphon, suck out the old fluid from the resevoir;
2) If the resevoir bottle is dirty, remove and clean using spray-brake cleaner; let the brake cleaner evaporate, and rinse with some new suspension fluid;
3) inspect (and replace) the hose between the resevoir and pump;
4) install new suspension fluid filter;
5) fill to max with new suspension fluid;
6) attach tubing to return pipe and let the other end go into a clean empty container (prefer clear);
7) start car and have an assistant bounce the rear suspension;
8) you will begin to see the old fluid come out of the return-pipe and into your container- the new/clean fluid in the resevoir will begin to go down;
9) when the resevoir is almost empty, fill with another liter of new/clean suspension fluid;
10) bounce the rear suspension until about half to 3/4's of the resevoir is flushed (the system holds about 1.5-liters);
11) turn off car, top off fluid, remove tubing, replace cap.

BTW- you could bleed using the bleed valve at the self-levelling controller, but that would mean crawling under the car and/or lifting it.

Good luck,
:-) neil
1988 360TE AMG
1993 500E