How do I add DLCs

[ᴅᴇᴍɪɴɴ]

I bought and installed American Truck Simulator. I bought the southwest pack+Washington. At the time I didn't have the money but now I bought several more states. How do I install those or do I have to uninstall and reinstall everything

[Pscht]

If it doesn't download automatically (or at least schedule downloads), right-click on the game in the client, Properties, DLC, check the boxes you want.