How do you open a Mazda 3 key fob?

To open a Mazda 3 key fob, locate the small slot or notch on the side of the fob. Use a flathead screwdriver or a coin to gently pry apart the two halves of the fob. Be careful not to apply too much force to avoid damaging the casing. Once opened, you can replace the battery or access the internal components as needed.