I have been doing my oil change by myself since a tech. at jeffy lube broke the drain plug in half on my car.
Things to remember without worrying about the numbers of torque:
A. The filter housing depends "heavely" on the rubber 0 ring to seal and so does the drain plug (metal O ring included with the filter). As such I only snug the drain plug with the rachet head but not the handle. Screwdriver turns type of a deal.
B. You can not afford to overtighten either of them.
This tells you one thing: better a bit loose than stripping the threads or worse breaking the plug (BMW plugs are HOLLOW metals. As such don't worry about specific number of pounds per whatever; you'll get used of it once you develop a feel for it; just like I did.
I hope this helped you out a bit.