The 2007 Mercedes-Benz ML350 is a relatively difficult vehicle to maintain, and is only recommended to those with the correct tools and experience in vehicle maintenance. You will have to remove a large panel from under the vehicle for access to the petcock. This will require you to contend with gravity as you complete. Changing the cabin air filter with reliability will be a problem, as you will need to use many tools in order to remove the glove box. The engine air filter is also more complicated to access than usual. For both of these filters you will need to remove torx bolts. The tools necessary may not be readily available for a repair.
Some things are easier on the 2007 Mercedes-Benz ML350. 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. Changing the headlight is no problem, as you only have to reach behind the housing for access. Checking the oil level is easy to do, as the oil dipstick is easily accessible in the engine bay.
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.