Finish the fish here.....
Next, insert two wires thru the hole you drilled and pull about 16" thru the hole in the fish so you have the wire doubled thru and pull the fish out from the housing end. and pull about 8" of the wire out for your connections.
Now, place the rotating connection back in, making sure that the new wire follows the channel with the defrost wires. The connector has a flat spot so you can't put it in the wrong way. Then replace the top of the connector making sure that it rests between the plastic posts. Then insert the new wires and the defrost wires in the slot in the cap and snap it back on.
Fish the other end of the wire out near the white connector plug and replace the foam plug and foam backer on the mirror.
Locate where you want the lights mounted and drill the appropriate holes for the mounting screws and wire. Install the lights. I used the provided screws and then shot them with black paint where they protruded so they didn't show. I held the lights back 1 1/4" from the edge so they wouldn't interfere with tilting the mirror.
I don't know if this matters for final connections, but make sure you use a continuity tester and mark both ends of one of the wires so you know which wire is flasher and which is courtesy.