The other option, and the one I happen to prefer, is to right click on your Microsoft Games folder where you have all of your CFS2 installs located.
In properties, click on the "Security" tab. Then click on "Edit". Then highlight your profile name and Administrators and check the "Full control" box under the "Allow" heading.
Now, click on the "Advanced" tab below that box. In here you look at your profile and Administrators profiles and make sure that it says Allow under "Type" heading and Full control under "Permissions" heading and gives those permissions to "This folder, subfolders and files" under the "Apply To" heading. If it does not, click on the "Change settings" tab and give yourself those permissions here.
Once done, close out of that and restart your system and you will have editing permissions for every single file in ALL of your CFS2 installs.
When you install a new CFS2 into that main folder, it inherits the permissions and you will have edit rights to all files in that new install. If not, then you now know how to get them.
This way, you do not have to open your PC to not having UAC on. UAC is a first line protection for your computer against hacking. I prefer to have mine turned on.
PS
During the above process, you will see it run through folders and files giving you permissions on them. Just let it run through them. If you have a bunch of installs, it may take a few seconds/minutes. Also, it will give you error messages on air files and mdl files. Just click on "continue" and let it run its course each time. Once it is done, airedit and mdl converters will also work on these.