So the nested link from your link had this info:
Here's how (I think) I did it:
- remove all drivers with DDU;
- unpack Catalyst Omega drivers;
- unpack latest Beta drivers;
- unpack December 2014 Bootcamp drivers;
- replace the entire contents of the Bin64 subdirectory in the Beta drivers' directory (in c:\AMD\) with the entire contents of the Bin64 subdirectory of the Omega drivers;
- replace the Installmanagerapp.exe and installmanager.dll files in the Bin64 directory of the Beta drivers with the same files from the Bin64 directory of the December 2014 bootcamp drivers;
-run setup.exe in the beta drivers unpacked directory.
I lost my catalyst control panel in the process (despite registry cleaning) but, who cares about that if crossfire no longer needs to be switched off for GTAV???
From the above, it's still unclear to me. First he states "he thinks" his instructions are correct. I also don't know what DDU is. And then there's still control panel issues after he completed his process. Not very confidence inspiring to a relatively new Mac user. But thanks for pointing it out anyway.