I have been OK doing my 87 300E and 95 S420 using the Motive Power-Bleeder unit purchased ? either at Fastlane (here) or was it Performance Products, can't recall. It is fairly easy to do, but does require the max pressure. My tank will pump up to about 30 psi. Just open one wheel at a time and let it "bleed" out until you are sure you are getting new clean fluid. Close that bleed screw, re-pressurize the tank (checking that you still have enough new fluid in the pump up tank) then proceed to the next wheel. Keep everything really clean and use brand new fluid everytime.

DanielW