In American Truck Simulator it’s easy to install mods.
Just follow this few easy steps below:
Copy and paste mods in: C:Documents/American Truck Simulator mod folder.
After that you need to activate the mods you want to use.
Mods are usually in .scs format files, but sometimes mod files can be compressed in .zip and .rar archives.
Unpack using 7zip or WinRar.