LiveryAircraft Questions

I’m trying to understand the process of building a repaint for a 3rd party aircraft in MSFS.
I would like to know what this means

  • SimpleAircraft_FUSELAGE_albd_000.png
  • SimpleAircraft_FUSELAGE_comp.png
  • SimpleAircraft_WINGS_albd_000.png
  • SimpleAircraft_WINGS_comp.png

I took 2 texture files in PSD from a third party aircraft which I converted to a PNG file.
In PackgeSource\SimObjects\Airplanes\MyCompany_Livery_Aircraft_Alu\texture.alu I put these 2 files.
For these 2 files I replaced the name with SimpleAircraft_FUSELAGE_albd_000.png and SimpleAircraft_WINGS_albd_000.png

The Package came out very well, the files were milled into PNG.DDS
I understood how the process is done.
I have 7 files for a new repaint, and I haven’t yet figured out how to output these files using the comp.png files in the example!
An explanation ? a step-by-step explanation ?
Regards
Marc