You need to have access to the truck and see the labels in the actual part to make more sense of the diagram.
Get the part and some solder and soldering iron.
Unfortunately, we need learn how to read electrical diagram a little bit.
At least, that is my advice.
Somebody probably have done a photo or check youtube. Not sure.
Or you can use the 3 bar map as you see in your other thread.
Which is more of a plug and play.