I had Lou build mine as well, didn't have the confidence nor time to open up the headlamps. I opt'd for the D2S 5.0, based on the reviews, as it's a bit wider than the Mini H1 (supposedly) and I like the igniters right on the bulb.
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@Flipped Bezel, I highly recommended the upgrade as well, I haven't taken the truck off-road yet, but even on road it's a big improvement over the halogen projectors.
I did provide the link for the brass inserts. I don't have any files or dimensions on the plate used to mount the bracket. I used paper to poke a hole on three of the mounting holes to get a template of where to drill the holes, placed said paper on a table, placed the ballast on the paper and drew out how I imagined the plate to be. It took several tries, had to cut down the plate a few times for the best fitment.
If you look underneath the headlight, from under the bumper, you practically have clear access to the three mounting holes to the plate. While there isn't much room, there is somewhat decent access.
I can provide some photos later this week.