Suppose you must move your MAILBOX Alert Extended Range Set to another location or re-configure it to use another WiFi network. In that case, you need to delete the information already stored there. 

To do that, unplug the extender from the power outlet. Using a flat screwdriver or a dull knife, pry open the device enclosure using a slit through which wires to the sensor are coming from. Press and hold the CLEAR button while you plug the device into the power outlet. Hold the button for 15 seconds, and after that, you should see a steady blue light on the blue circuit board, indicating that the device is ready to be  configured with a new WiFi network.

Your device has now been cleared and can be unplugged and moved to another location or re-configured to use another WiFi network.