it is easy to do really....but you will nead to use a 3 way switch at both ends..(has 3 screw terminal on it) and for the new switch location you need to run 3 wire with ground (total of 4 wires in insulation sheath) from the new switch to the first light, then you need to add a new single conductor insulated wire same gauge as the existing wire, either 14 or 12 from the existing switch location to the light you ran the other switch to. then follow the instructins on the wiring diagram that comes with the swtiches or the instructions at the website above ad this should work...Good luck and post back up if you have further questions and to let us know if you were able to get installed and working properly.