The Stone uses a CR2032 battery. To replace its battery, please follow the steps below. We've made this handy video, or you can follow the written directions below. These directions are for the 1st version of the Stone.
1. Hold the Stone on its side so the keyring hole is facing directly up.
2. Gently insert the ball point pen into the keyring hole and apply light downward pressure until the Stone shell splits open.
3. Remove the old battery from the triangle contacts and insert your new battery with the positive contact facing upwards. (“+” side up!)
4. Place the Stone Button side of the plastic on a flat surface and align the front of the Stone plastic on top. Press the two pieces together firmly until the sides are closed.
5. Press the Stone button and verify that the LED flashes.
Please note: If the light does not flash, repeat steps 1-3 and verify that the battery is inserted correctly. If the device does not turn on after replacing the battery, please reach out to firstname.lastname@example.org