Simplify the Mobile Hamburger MegaMenu - Prestashop Theme

We are developing a new website in Prestashop with a theme that don’t have the functions to customize the mobile menu as we want. Actually we have this situation: 1. Hamburger menu on top-left 2. When somebody click on the Hamburger Menu, it open the composite menu with 2 subdirectory 3. Clients must click on Categorie to see the real menu (we want to show them since the first click on the hamburger) What we want: 1. Hamburger menu on top-left 2. When somebody clicks on it, it shows the internal Categorie menu (see the attached file for the images that explain better) We need to reply this edit by ourself, so you have to describe to us how to reply this, because it could happen that we have to update the theme very very soon so it’s important that we can insert this edit by ourself. We will pay for full working solution and also for complete explanation of how to reply this edit. Please offer only if you are skilled to easily do this job and be aware that the work must be completed in the offert time. In the attached document you will find more instructions about the live website and the files that manage the megamenu of the website (I’m not sure that this is enough to evaluate the work, if not, please ask what you need to valute it, thanks.) The Megamenu zip file contains part of the code that manage the megamenu. If not sufficient to value, please ask what you need, thanks.