To change away from the default data you need to create new data and settings files.

"server_packages.sii and server_packages.dat must be generated manually via calling `export_server_packages` command while normal game is running."

To do this goto your PC's documents folder then American Truck Simulator. Find file "config.cfg". Look for g_developer and change setting to 1. Then find g_console and set to 1. Save.

Run your game, goto continue game the hit ` key (tilde key), this will bring up console. Enter export_server_packages and wait until it says packages exported.

Goto your folder previously (documents\american truck simulator) and copy the to files - server_packages.sii and server_packages.dat to the server through tcadmin file manager. (make sure server is stopped). Place into the American Truck Simulator folder.

Restart server. If all done correctly server should be running with your new stuff.

Any issues let us know.