You are already half way there. You don't need an adapter harness. Simply move the pins around in the original connector block and press the cap back onto the block.

I used an ohmmeter to determine which pin of the headlight assembly went to which light and marked it down. Then I used a voltmeter to determine which pin provides which function. Then simply rearranged the pins in the connector and plugged it in. No big deal.

Good luck,