Download the plugin zip file by clicking on the link within the email you received after purchasing, or from the purchase confirmation page.
Visit your WordPress admin area and click on Plugins > Add New
Click on the Upload Plugin button.
Click on the Choose file button that appears and select the zip file that you downloaded. Now click on the Install Now button.
Once the installation is complete, click on the Activate button and that’s it. Your plugin is now installed.
To add your license key, go to the WPGetAPI menu and click on Licenses. You can copy your license key from the email you received or from the purchase confirmation page.