The drain plug is located on the oil pan directly below the engine. It is a 13mm bolt. Remove the drain plug and allow oil to drain. Next locate the oil filter housing on the rear of the motor. It is a black plastic cylinder with a 22mm size plastic nut on top. Unscrew the filter housing and remove the paper filter element. Replace with new filter. Reinstall filter housing and drain plug. Do not over tighten filter housing as it will break if you tighten with too much force. Next unscrew the oil filler cap on the top of the engine valve cover. Fill with 5.5 qts of fully synthetic oil. I recommend Mobil 1 on all MB engines. Run engine for a few minutes and turn off. Check oil level with dipstick and add oil if correction is needed.