over 2 years ago - AndrewT - Direct link
The steps are the same on MacOS except for the antivirus part.

**File Locations on Mac OS X**
The executable and DLC folder are in Users/USER/Library/Application Support/Steam/SteamApps/common/Crusader Kings III/
To see it go to the Finder, hit command-shift-G (ie Go To) and type in ~/Library/ .
The user files (settings.txt, error logs, saved games, gfx, mods) are in /Users/USER/Documents/Paradox Interactive/Crusader Kings III/ .