The 2009 Mercedes-Benz C300 Sport is a relatively difficult vehicle to maintain, and is only recommended to those capable of vehicle maintenance. You will have to peel back the wheel well lining for access to the fog light. This lining can grow tight to the vehicle and be difficult to peel back. Accessing the oil drain plug with reliability will be a problem, as you will have to remove a large panel from under the vehicle for access. This will require you to contend with gravity as you complete. The engine air filter is more complicated to access than usual, and will require more tools than usual.
Some things are easier on the 2009 Mercedes-Benz C300 Sport. Changing the headlight is no problem, as you only have to reach behind the housing for access to the assembly. Many of the tail light bulbs are easy to access behind an easy to remove access panel in the rear of the vehicle. The components of the spare tire are easily accessible in the rear of the vehicle. This keeps the tire and jack kit ready to go in case of emergency.
Hans Angermeier has produced over 100,000 videos showing drivers how to fix things on their cars. He has broad expertise on basic repair procedures covering the majority of cars on the road.