I have a 2011 Edge, so this is based on that model.
The dust cover will need a 1" hole drilled through the center. A regular 1" spade type drill bit will work just fine. The light kit comes with a grommet that will fit the 1" hole in the cover. All necessary wiring passes through that grommet to connect the factory wiring and the HID wiring.
It all worked out fine on mine. No other modifications were needed.