Turn the unit upside down. Press the red lever until it releases (you can hear, feel and see that). Next to the red lever, the lid has a clear lever … wedge a skinny object (little screw driver or similar) and press the clear lever in the direction of the battery pack until the lid releases. Gently try to wedge the lid open & possibly at the same time pull up on the large red piece at the top of the unit. When closing, be sure the clear lid is closed last.