I used the lead on my right headlamp. Remove the grill and then the headlamp assembly and unplug the wire loom. The center black wire on the loom is ground. If I remember correctly, the high and low beam wire are the same color. You can use a multi meter to track down which is high beam. If you don't have a multi meter, a test light will work fine. When you figure out which is which, you can use a wire tap to connect your lead from the relay to the high beam.

Note: before you remove the headlamp assembly, use a marker or grease pencil and make a small mark at 12 o'clock on the bulb and retainer ring so you don't waste time trying to figure out how each is aligned.