I just did the oil change on my 92 500 SEL. The oil drain plug is located along the rear edge of the drain pan in the center. Follow the directions here on Mercedesshop but the key thing is, the copper washer that comes with the filter kit is the replacement for the washer on the drain plug. I made the mistake of following what was on my car and I put the washer on the shaft of the bolt that goes through the top of the oil filter housing. I had to drain the oil back out into a clean container, change the washer and refill the engine. Also you will have to take off the plastic encapsulation below the oil pan to get to the plug. Try to seat the filter in the housing straight so that the bolt will line up. I did this before sliding the lid all the way on. I used 8-1/2 quarts of Mobile 1. You will find this information in the back of the owner's manual. Of course you could use the topsider and not even go under the car. If you do go under, SUPPORT THE CAR WITH JACK STANDS!!! Do not rely on the jack. I used ramps and the stands as an extra measure of security. Good luck