Sorry if this sounds stupid, I have searched the threads and come up empty. I don't have a topsider, so if someone could point out the location of the engine oil drain plug it would be appreciated (1993 E300D). Thanks.

It should be underneath the front area of the car.
If you have the engine cover you must remove it in order to see the drain plug.

I found a great link on this site to another site that showed the location ("Braingear" I think), on the right side of the oil pan facing the car). I figured that was it, just never worked on a diesel before. The oil filter is certainly more convinient than any gas car I have worked on.