UltraSync Modular Hub
Note: You will need an Alan screwdriver.
Unscrew the cover and open the device (the screws will not come out all the way).
Locate the battery.
Remove the wires from the battery terminals.
Attach the wires to a new battery (12V), ensuring the red and black wires match up with the terminals of the same colour.
Place the battery back in the case, making sure it is seated in all the way.
Replace the cover and tighten the screws back in place.