To update to the latest version of the theme you have a few options.

NOTE: Before updating the theme we strongly recommend you backup your live theme instance first! We also highly recommend you first conduct updates on a staging/development version of your site to ensure you conduct a full test of major theme and plugin updates in a safe environment before going through the same process on your live site. (Good WordPress hosts like Siteground offer the option of testing theme and plugin updates in a safe staging environment)  -

We also assume in this update process that you have made no changes to the theme files yourself. If you have you will first need to move those changes to a child theme. We include a starter child theme in the main zip package which can be downloaded from themeforest. You can read more about child themes here:

1. Go to your ThemeForest account and download the latest version of the theme. The Installable file only version.
2. Install this plugin on your site:
3. Upload the new version of the theme via: Appearance > Themes > Add New
4. Go to 'Plugins' and disable CommerceGurus Toolkit, Layerslider and WPBakery
5. Go to Appearance > Install Plugins.
6. Update all 3 plugins and re-enable.

Video on how to update plugins that come within a ThemeForest theme: