here are the steps to replace the battery in your car key fob:
1. Lift the old battery out with a screwdriver. Most key fob batteries look like a small, silver coin and are usually located in the center of the fob.
2. Slide the new battery into place in the same position as the old one.
3. Press the 2 halves of the fob back together.
4. Test the key fob to make sure it works.
If you're not sure what type of battery you need, check your owner's manual or look for the battery type embossed in the plastic on some key fobs. This way, you can go to the store and select your battery before you need to open up the fob.
