The coolant drain on the block is on the passenger side just in front of the starter motor. It looks like a short stub of pipe with a hex nut so that you can get a wrench on it. I thought I had a photo but don't or at least can't find it. Once you have the drain loosened a bit (takes a bit of torque and the location is not the best, must access from underneath) you can put a hose (1/2 inch ID worked for me) in the little pipe so the coolant drains into a pan and not all over the ground and you.

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970