For the Select controller press and hold the minus button (-) until the unit flashes then disconnect the system. For the Edge controller, press and hold both the plus (+) and minus (-) buttons and then replug the unit.
All Trimlight Systems:
Select System- Press and hold the minus button (-) until the unit flashes a quick red and then unplug the system.
Edge System- Unplug the unit, then press and hold both the plus (+) and minus (-) buttons while doing this replug the unit in.
The way to tell if you have either an Edge controller or a Select controller is to see in the top left corner of the controller, if there are 3 lights then you have the Edge controller. If you do not have those lights in the top left then it is the Select controller.