I made a little more progress, but still don't have a light finished.
I had thought that the pins from the LED adapter cable would work in the headlight connector. They are smaller and latch on one side, where the original pins latch on both sides.
If your wires are still good, it's probably best to cut them and do a crimp connection to the wires for the LED light. Since my wires are bad, I soldered the last .5 inch with the connector to the LED wires.
Without fully assembling them or aiming, I stuck it in the car to check on progress. It is a clean white light, not too blue or yellow. The turn signal blinks very fast. I think that having the original turn bulb also installed will correct that. ...or just wiring the amber LED in as 'Fog' or 'Parking'.
The lights work on dim right now, but not bright. There are two grounds in the headlight harness and I only have one (common) connected. The LED light only uses one ground for both bright and dim. I still want to get a look at the wiring diagram to trace where it all goes before I decide how to connect it.