Reorganise and modularize Javascript

We have recently overhauled our website with the help of an agency, however this process has left with a single JavaScript file of about 40,000 lines of minified and/or compiled code. The project is to split each module into a separate file so that my development team can safely call any module without fear of breaking scripts further down. We expect that the end product to be no more than two external files ([login to view URL] and [login to view URL]). Ideally we should be able to edit each module at its source and adapt our existing Gulp stack to apply the necessary transformations on each module that we can load into our site. Please take a look at the uploaded files for a diagram of where we are and what we need to have done. In additional to being exceptionally fluent at JavaScript, you should also have a solid amount of experience using Webpack and a basic understanding of Vue.js would be beneficial. This project in essence requires you to merely organise, modularize and otherwise make it exceptionally tidy - amending the code as required. We are happy to communicate with you through our own business instant messaging program when you are successful.