I know it doesn't look very good, making liveries in this game is super tedious.
You should be able to drag and drop into content manager but if that doesn't work just drag the content's folder from the file to your assetto corsa folder
First time making a livery, I couldn't find any love chunibyo skins so I made one myself.
You should be able to drag and drop into content manager but if that doesn't work just drag the content's folder from the file to your assetto corsa folder