its fairly simple...cut and splice, drill a small hole, done! You gotta reroute the positive wire that turns on your stock ballast(usually a red wire ) to your aftermarket ballast. Secure the aftermarket ballast somewhere and drill a small hole on the back cover to get the HID wires inside. Most aftermarket HID Kits come with a small rubber grommet , use this to seal the hole properly. good luck!

 

oh yeah, you will still need your stock ballast unless you have a better idea on how to cover the 5 inch hole in the bottom.