Editing main.js
The latest version of The7 uses minified version of js and css like main.min.js, main.min.css etc.
If you want to modify main.min.js, please edit main.js and minfy it using tools like http://javascript-minifier.com and save it as main.min.js
You can also rename the main.min.js to some other name like old-main.min.js or delete the file. So theme will use main.js