To enable Rich Prescence, first you'll have to download Dusty's mod from the Workshop and the Discord Rich Prescence library from GitHub[github.com]. Subscribing to the mod itself should be enough for that, however the library is more involved.

You'll want to make sure you download the Windows edition, so click on discord-rpc-win.



Open the downloaded ZIP file, and navigate to discord-rpc/win64-dynamic/bin. You should see two files: discord-rpc.dll and send-prescence.exe. Set this Explorer window aside, and continue to the next step.



Please note: This was written for users of 64-bit Windows. If you are on 32-bit, navigate to discord-rpc/win32-dynamic/bin instead.

Go to your Steam library, and right click on RimWorld. Click on Properties.



Click on Local Files, then Browse Local Files.



Navigate to RimWorldWin64_Data\Mono.



Copy and paste the discord-rpc.dll and send-prescence.exe files into that folder, and rename discord-rpc.dll to 0discord-rpc.dll. You may now close both windows, and start your game.

Enable the mod in the Mod menu, restart the game, and enjoy.