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.) Use the Envato WordPress Toolkit

2.) Use the Easy Themes and Plugins upgrade plugin

3.) Manually via ftp

- download the existing version of your theme in /wp-content/themes/

- put it in a safe backup location

- delete the live version of the theme

- re-upload the latest version