You now have access to the battery and microSD card.

If you want, you can replace the microSD card with a different capacity. You can also take out the existing microSD card, put it into a reader and plug it into your computer. This can help you check the footage and see when the camera stopped functioning, though not necessarily why.

Unplug and remove the battery, always being careful not to pull directly on the wires (even though we all do it).

Unfortunately, the contacts on the connector are really small, so measuring the voltage on the battery is difficult.