1. Gather the necessary tools:
- Small flathead screwdriver
- New CR2025 coin battery
2. Locate the key release button:
- On the key fob, you'll find a small button or switch that says "Release." Press it to release the mechanical key.
3. Pull out the mechanical key:
- Take out the metal key from the key fob by gently pulling it out.
4. Pry open the key fob:
- Use the flathead screwdriver to carefully pry open the two halves of the key fob. Be careful not to damage the plastic cover.
5. Remove the old battery:
- Inside the key fob, you'll see the old CR2025 coin battery. Use the flathead screwdriver to gently remove it.
6. Place the new battery in:
- Take the new CR2025 coin battery and place it in the key fob, ensuring the positive (+) side faces upward.
7. Put the key fob back together:
- Align the two halves of the key fob and snap them back together. Make sure it is closed securely.
8. Test the key fob:
- Press any button on the key fob to ensure it works correctly. The LED light should illuminate, and the key should function properly.
9. Insert the mechanical key:
- Slide the mechanical key back into the key fob.
That's it! You've successfully replaced the key battery for your 2002 c240.
