It will have to be re-id'd into the programming then refreshed. and updated if it isnt already a switch at that operating system level.
The switch will work with programming as a dimmer until you add it in, so don't worry about leaving them in the dark. :)
Dont blame the installer yet... maybe the customer decided to swap the 75-100 watt bulbs in the place of the old bulbs and didnt see it as an issue until it melted.
