How change a battery 2008 X3 BMW key?

To change the battery in a 2008 BMW X3 key, first, locate the small notch on the side of the key fob and use a small flathead screwdriver to gently pry it open. Once the fob is split, remove the old battery, which is typically a CR2032 coin cell, and replace it with a new one, ensuring the positive side is facing up. Reassemble the key fob by snapping the two halves back together, ensuring they are securely closed. Test the key to ensure it functions properly.