It's pretty straightforward once you have all the parts in hand. Keep in mind that the original links have all been superseded to the new-style ones on the W210 and you'll need a "bolt kit" for the camber, thrust, and torque links. The toe link can be a bit stubborn but should come loose with a BFH. The rear axle must be level when torquing everything down. I did this by first measuring from the center of the wheel cap to the fender lip, and then raising the axle (underneath the spring arm) until the distance from center of the wheel hub to the fender lip was the same as my first measurement.
-Aaron 1987 300D
