If you're doing it plan to do 2 sets, the lights come in groups of 4 but you need 6. Sell the other set to pay for your own, or give them to a neighbour. Print orientation in 3mf is what I found to work the best for minimizing supports and keeping the adapters strong

Parts required:

12x printed adapter brackets (3-4 walls, minimum 15% infill)

6x 4x6" LED lights - try to find ones that are tapped on the back case, the photos in the descriptions will always show that they are but a lot of times when they show up are not. Pretty hit or miss

24x 10-32 ¾" machine screws

6x H4 wiring adapters (if the lights you buy don't come with)

6x 2.8mm male spade connectors and insulators

8x 6.3mm male spade connectors and insulators

Optional:

6x Ferrite chokes for 7mm diameter wire

Print 12x adapters, I use a small impact to start the machine screws into the adapters, narrow high side. Run them flush to the bottom of the printed part. Set aside for later.

The inside two lights run high/low. If your lights came with adapters - take two adapters and cut the 3x 7.8mm male spade connectors off. Insert insulator on wire, strip and crimp on new 2.8mm male spade connectors on all three wires. Outside 4 lights only require power and ground, leave the middle (low beam) wire. Follow same procedure as above but crimp 6.3mm male spade connectors on +/- wires.

Bench test adapters and LEDs (I've gotten new lights with bad LEDs) to double check connectors.

A small impact driver or drill makes install a lot easier. Need a Phillips and Robertson bit (depending on machine screw head). Remove 8 screws from each bulkhead, unplug wires and set somewhere that’s easy to work. Remove four screws from each light. I go from the other side of the panel (front) and run the screws into the adapters. Line up lights with adapters and start each screw before fully tightening.

Don't over torque adapters. Tolerances are tight enough that it acts like a nylock so just snug them up.

All of the LEDs are the same so location doesn’t matter. Before lifting up bulkhead, connect wiring adapters to corresponding factory wiring, each is color coded. If your combine has two red wires in the middle light plug just go middle wire to middle wire on the adapter. I use electrical tape to cover the connections so the birds don’t pull them apart. Lift up bulkhead, plug in lights and secure with original screws. High low functionality is retained, test them out.