Your sensor checks for the latest software daily - and if available, will update itself. You should not need to do anything. 
If you wish to do a factory reset, you can push and hold the Reset button (on the side of the device next to the USB port) for 10+ seconds. This will erase all Wi-Fi configuration settings so you will need to repair your sensor using the instructions in the mobile App.
If you wish to change your connection option, unplug the ethernet and power cable for at least 10 seconds. For the Arctic Fox model, plug the Wi-Fi dongle (not needed for the Yellow Mongoose and Black Panther models) and power up your sensor.
