Hi
The camera plist file that you are looking for is in the library rather than the user library.
Obviously you need to have the Canon plug in loaded first before you can modify it.
So just go to your Macintosh HD and open the library folder.
You then need to navigate to
/Library/Application Support/ProApps/MIO/RAD/Plugins/CanonE1.RADPlug/Contents/Resources
Should be there.
best wishes
Neil
http://www.patience.tv