Sounds relatively easy if you have the schematic. Primary side of relay would have power wire tapped into key-hot power.. then a ground to the firewall. Secondary side would tap into power feed to the switch. The only tricky part would be tapping in to all outputs of the switch.. as it is multi-position. Secondary side output would have to tap into the output leads from headlight switch for park lights, headlights.. and fogs if you wish. Would just be a matter of finding the wires corresponding to switch position i would think.