Here are the steps to access the battery:
1. Open the trunk of the vehicle.
2. Locate the battery cover on the right side of the trunk.
3. Remove the battery cover by pressing the release button and lifting the cover.
4. The battery will be located beneath the cover.
Here are some additional tips for changing a battery in a 2009 Mercedes E350:
* Make sure that the ignition is turned off and the vehicle is not in gear before you start.
* Wear safety goggles and gloves when working with a car battery.
* Be careful not to touch the positive and negative terminals of the battery at the same time, as this could cause a spark.
* If you are unable to remove the battery cover or the battery itself, you may need to take your vehicle to a mechanic.
