Installed off-road lights on my brush gaurd also. Mounted the switch on the side of the console. Wired mine so they owuld only work when the standard headlights were on. this way I could not leave the off road lights on and run down the battery. You will need wire, 12 ga or better, a switch and a relay. the relay is a common auto electrical item. They usually come with a diagram.
Wiring is as follows. Find a 12 Volt source when the headlights are on. From this run a wire to the switch. From the switch run the wire to a relay. I mounted the relay on a 2" X 2" plastic panel that is cable tied between the battery and the fender. On the panel is mounted a relay and all the attending wires are secured to the panel also. Back to the wiring, From the switch wire connect this to the energizing contact of the relay. There is also a ground connection on the relay. Since the relay is so close to the battery I made this connection with an alligator clip to the battery. From an always hot 12 volt source run a wire to a fuse, then to the "source" connection of the relay.The fuse will carry the load of the lights, check your lights for the correct size. The 12 volt source could be an alligator clip to the positive battery post. From the "switched" relay connection run a wire to the lights. A relay is a must as most switches cannot handle the amps of the lights. Also by putting the relay close to the battery there is no line loss as the run from the battery to the lights is minimal.