I fished the wires through with a wire coat hanger that I made straight.
I made a template from an index card, taped it to the headliner, drew the pattern with a pencil, cut the headliner with a razor knife, removed the headliner piece and the insulation, wired it up with some 14 gauge wire tied into the front dome light.
It was really easy and took me about an hour and a half.