First off, get yourself a 6-point 13 mm socket. A 12-point socket will round off your drain plug.
Step one, change the oil when it is hot, not cold.
Step two, remove two bolts on top of the oil filter housing, and lift up the cover. This will allow the oil to drain out of the filter. You don't have to take the cover all of the way out until after you drain the oil.
Step three, use your 6-point socket to remove the drain plug. Dispose of your used oil properly, we aren't living in the sixties any more...
The torque on the drain plug is is only around 10-15 Nm. Not too tight, you don't have to kill it, and use a new drain plug seal every time.
Now replace the filter and add the oil. Don't over tighten the oil filter housing bolts either.
Check for leaks when done and don't over fill it....
Change your oil at regular intervals. I just instaslled a long block on a 1996 S420 with 81,000 miles that had not seen regular oil changes....chain broke and it was sludge city inside....