1. Open the hood of your BMW.
2. Locate the battery, which is in the trunk on the passenger side.
3. Disconnect the negative terminal cable by loosening the nut that holds it in place.
4. Disconnect the positive terminal cable by loosening the nut that holds it in place.
5. Remove the battery hold down bracket by removing the two bolts that hold it in place.
6. Lift the battery out of the trunk.
7. Dispose of the old battery properly.
To install a new battery, simply reverse the steps above.
