For a local mod:

1. Subscribe to the mod you want to download.
2. Open File Explorer (If you're playing on Windows)
3. Navigate to your Steam Workshop directory ("C:\Program Files (x86)\Steam\steamapps\workshop\content" for me)
4 (Optional). Open the folder of the game you got the mod for. (Easily done by going into a Browser and copying the number near the end of the link, or middle-clicking the Workshop button in the Rimworld hub to open a page with the URL on-top of the window.)
5. Copy the Workshop ID of the mod you want, and paste it into the search bar in your file explorer (or equivilant) and then copy (CTRL+C on Windows, ofc) the folder.
6. Go to your non-steam Rimworld install directory
7. Paste (CTRL+V on Windows, ofc again) the mod into the 'Mods' folder.


In this case, you just need to subscribe to the mod and then go to this spot in the file directory:
C:\Program Files (x86)\Steam\steamapps\workshop\content\294100\2077443812
and then copy the folder AND its contents and put it in your non-steam version's mod folder.

https://github.com/FantasyFanGitHub/Rimworld-1.1-Decorative-Cliffs.git