How do you change battery in 2003 Hyundai Elantra remote door opener?

To change the battery in a 2003 Hyundai Elantra remote door opener, first, use a flathead screwdriver to gently pry open the remote's plastic casing. Once opened, remove the old battery, which is typically a CR2032 or similar type, and replace it with a new one, ensuring the positive side faces the correct direction. After replacing the battery, snap the remote casing back together securely. Finally, test the remote to ensure it is functioning properly.