Downloaded it ( took 45 minutes), now, it is an installer but not a .pkg installer, so I looked inside and there is a zip file inside, unzipped it and there's the App, some Extensions a bundle and Preference pane amongst some others, inside the Application I found another Zip!!! with even more files.
But, as I expected the files you want to edit are in the Application itself and the Preference Pane.
So, look inside both of these and you are good to go.
If you need anything else ask.