Before you update, it is best practice to always make a backup of your theme folder.
Download the new theme package from your ThemeForest account.
The theme is under “Theme” folder in the package.
Choose to upload the theme via FTP or via WordPress.
Update Your Theme via FTP
There are two ways of getting files onto your site, and once there, changing them.
By using an FTP client.
By using the file manager provided in your host’s control panel.
Go to “/wp-content/themes/” location and backup your current theme folder by saving it to your computer, or you can choose to simply delete it. Your content will not be lost. (The translation files are located under languages folder in the theme folder.)
Retrieve the new zipped theme file from your new ThemeForest download, and extract the file to get the theme folder.
Then simply drag-and-drop (Upload) the new theme folder into “/wp-content/themes/” location, and activate the theme in the “Appearance > Themes” section. (Choose to “Replace” the current one if you did not delete it.)
Update Your Theme via WordPress
You need to deactivate your theme in the “Appearance > Themes” section by simply activating a different theme. Once you activate a different theme, you can delete your theme. Don’t worry, your content will not be lost. (The translation files are located under languages folder in the theme folder.)
Then simply upload the new theme file in the “Appearance > Themes” section.
Once it uploads, choose to activate the theme.