You must install FSAutoLaunch.preferences in a directory that the Preferences application will check when it launches.  The usual place is in ~/Library/Preferences which is a Preferences folder inside the Library folder inside your home directory.

Once copied into this location, you should quit the Preferences application and restart it.  You should then see the Rockets icon in the Preferences window.   See the associated help panel that is available from from the FSAutoLaunch area of the Preferences window.