Where are configuration files? I want to mod…

I really like Estuary v2. The only thing I would like different is to be able to add a custom main menu item. I know that this can’t be done through the GUI so I was hoping I could tinker with some xml files and do it manually. The first road block is that I can’t find where the configuration files for estuary are located. Can someone help me find them? (If anyone has any tips on what I will need to change in what xml file(s), feel free to chime in as well.)