Use a paper clip to depress the spring bars and remove the watch band from the watch case.
Use the small jeweler’s (Phillips head) screwdriver to remove the three screws on the back of the watch case. Remove the back half of the watch case to see the circuit board.
Remove the circuit board from the watch case to see the attached batteries.Replace the batteries with the two alkaline button cell batteries provided, making sure the positive (flat) side of both batteries face up as shown.
Reverse steps 1-3. Place the circuit board with new batteries back inside the watch case. Secure the watch case using the original screws and replace the watch band.