1. Roll back the rubber cap until you can easily pull it off of the glow stick.
2. Remove the light.
3. Open the light from the back of the casing and take out the eLite Flow V2 Microlight.
4. Slide the dead batteries out from the bottom of the chip.
5. Insert 2 1620 batteries under the battery arm, with the logo side visible.
6. Snap the casings back in place around the chip.
7. Insert the light back into the bottom of the rubber cap.
8. Place the rubber cap back on the glow stick and unroll it until it fits tight and secure.