What he meant is that initially installing Cubase 8 will borrow preference settings from the highest installed previous version.
If you want to start from “scratch”, you merely have to trash the Cubase 8 Preferences folder and re-launch Cubase 8. It will rebuild it’s preferences folder anew, minus imports from earlier version preferences. For safety, don’t empty the trash after doing this. Drag the old folder out of the Trash to some other safe location.
The pathway to the Cubase preferences folder on 10.8.5 is this:
Your boot HD/Users/[your name]/Library/Preferences/Cubase 8
If you can’t see your User/Library folder on 10.8.5, do the following:
Method 1
In the Finder, choose Go > Go To Folder.
In the Go To Folder dialog, type ~/Library
Click Go.
Method 2
Hold down the Alt (Option) key when using the Go menu. The user library folder is listed below the current user’s home directory.
Method 3
The following method makes the user library folder permanently visible.
Launch Terminal from Mac HD > Applications > Utilities.
From within Terminal type the following command and press Return:
chflags nohidden ~/Library
Enter the system administrator password, if prompted, and press Return.
Close Terminal for this change to take effect.