You can update your theme with the Envato Market plugin.
Alternatively, you can update it manually by following these steps:
1. Log into your ThemeForest account and navigate to your Downloads page. Find our theme and click on the Download button next to it. Choose Installable WordPress file only.
2. Extract the downloaded zip file. Inside, you’ll find a single folder:
3. Log into your server via FTP. Navigate to wp-content\themes and drop the theme folder in there.
When asked if you want to replace the existing files, choose Yes.
4. Log into your WordPress admin panel. Navigate to Theme Options and click on Save in order to generate a new dynamic CSS file.
Your theme is now updated. Next, you can update plugins.