Instructions

1. Install the game using the FIFA 12 Installer in the FIFASoccer12.dmg
2. (Perhaps optional) Run the application and download/install the update when asked.
3. Right click and select Show Package Contents on the FIFA12 application.
4. Copy the included FIFA.exe file  to:
 /Contents/Resources/transgaming/c_drive/EA Sports/EA Sports FIFA Soccer 12/Game/
5. Overwrite the existing FIFA.exe
6. Block connections with LittleSnitch, it will try to connect to EA
7. Enjoy

Notes: The Update and LittleSnitch blocking might be unnecessary, that is just the way that I've tested it and it worked.

-DCmac