Ground your black wires of the 3 lights. Take the pos + wire from each light, wire them together along with several ft of wire to run through the firewall inside cockpit.
Then for power you can either wire off the cigarette lighter that has the continuous current or I ran a seperate hot wire with a fuse from the battery through the firewall.
When you located where you want your switch, attach the hot (red wire) to the + post.
Then the pos + from the lights to the middle accessory post. And lastly a ground wire to the third - post. You're done.
Just did mine so it's still fresh in my mind.