The easiest and safest way is to update through the Envato Toolkit plugin that comes packed with the theme.
In your WordPress admin dashboard you should see a section called Envato Toolkit. You need to connect your ThemeForest account to it and once you have done so, you’ll see here all available updates, always at one click away.
- Navigate to the Envato Toolkit section in your WordPress admin.
- To connect your ThemeForest account you'll need to enter the username in the "Maketplace Username" field and a input a Secret API Key.
- The Secret API Key can be generate in your ThemeForest account, in the Settings > API Keys section:
- Label it and click the "Generate API Key".
- Copy the API Key and go back to your WordPress admin panel, to paste it.
- Now that you've connected your ThemeForest account to your site, notice a 2nd tab called "Themes", you'll always be able to come here to update the theme.
- Click the "update automatically" link and your theme will update to the latest version.