Pretty much plug and play. They came with a rubber cup looking piece for each light. You have to cut a hole into the plastic piece that fits on the back of the headlight housing that protects the bulb. The rubber piece that comes with the setup goes over this hole, basically extending it out, to make it deeper. The LED headlight bulb itself is a lot deeper than than a standard halogen, so this creates the extra room needed.
It’s a tight fit to get everything in. I had to loosen up the battery and scoot it back and then take out the air box on the other side while working on it all. It all fits together when it’s done, just a snug fit.