You just have to connect a USB cable to USB port on the right temple and another USB cable to the USB port on the left temple. Both the USB cables must be connected to the charger. The two temples charge together, so it’s important to connect both cables to the glasses. The charge is complete when the blue lights (one on the right temple, the other on the left) are both on. If you still see two red lights on, it means that the glasses aren’t fully charged yet.