Right off the alt. Then run your switch wire for the relay to the outside of the clutch filler there are 2 holes there that you can pass wires through. On the other side there is a cover on the dash that you can pull off (bottom right theres only 3 screws it also has the dash dimmer switch on it). Splice into the dimmer switch wire as your switch power (that way you can't leave the lights on by accident). And then you can mount the switch in that same panel.
I am going to do a right up on aux wiring one of theses days.