1. If you are a user already bought this kit and want to upgrade the new features just go to the Opencart Admin panel menu 

    Extension>Installer

    Remove the old extension from the menu and install the new extension which is under the upgrade folder.

2. Go to Extension>Modification folder and just click refresh

3. Don’t do any other operation in the Extension>Extension folder

4. And follow the same steps as per the Extension Setup procedure document