The FS-ATC-Chatter.zip file contains the player and 400 or so U.S. based clips in the Regions folder. Due to their size the purchased clips are broken up into separate zip files which you must download from your Gumroad Receipt or your Sim Market account depending on where you purchased the full clip set.
Each of those zip files will contain a Regions folder that must be merged with the demo Regions folder in the main FS-ATC-Chatter folder.
The full installation instructions with images can be found here: FS-ATC-Chatter Installation
