I just did it on my 1994 E420. No spring compressor necessary to change the front upper mounts. Remove the center nut and the 3 others holding the mount. Place chucks at rear wheels for safety. Jack the car under the frame (not the control arm) until the strut's thread almost clears the mount. Do not lift too far, else the spring might come loose. Support car with jack stand for safety. Manually compress the strut, and from under the strut tower (the wheel well) remove the mount and bellow, then the stop bumper if necessary. Assemble in inverse order, tighten mount nuts to 20 Nm and center nut to 80 Nm. As always, use common sense.

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2004 E500 4Matic 138,000 miles