so to install this mod is quit easy,
download the mod,
open the archieve(.rar) and copy paste the folder (Star_Wars_Soundtrack_Replacer)
in your main game folder (for steam user for example it in steamapps/common/X4 Foundations/extensions
if you don't have the extensions folder create one (remember there is a s at the end of extensions)
then open your game there should be in extensions tab in the main game menu the mod activated but the best way to know if the mod work and in running is by just listening the main menu which should now play a star wars music (which I'll let you discover.)
cant get past loading screen. As soon as I hear the star wars music it crashes to desktop