Instructions:
Download the package,
Extract it to your "custom scenery folder" or to your desired hard disk and create a link(rightclick-> create shortcut) to your "custom scenery folder"
Go to the textures folder included in the package and run Convert_General.bat for automatic textures conversion (uses cpu) Or _HPC_Convert_ASAP.cmd for fastest conversion of the textures (uses also nvidia algorithm)
Wait the completion and press Y to delete the old .jpg files. The process can take quite some time depending on your hardware, THE QUALITY IS ABSOLUTELY UNCOMPROMISED.
Start xplane to let it detect your new ortho tile
Edit your scenery_packs.ini being careful that the "airport_name" ortho entry is BELOW the airport scenery
Enjoy