Here are the steps to install pro theme or upgrade from free theme to pro theme:

1. To install or upgrade from free version to Premium version you will need to buy our premium theme, go to this link to buy our premium theme
2. After you purchase our pro theme you will get a license key via email or log in to my-account
3. Click on View Details and Download, you will be redirected to purchase confirmation page there you will see your theme name click on that button to download theme zip file
4. Log in to the WordPress Administration Panel
5. Go to Appearance => Themes =>Add New
6. Click on Uploads => Upload Theme and Browse the downloaded zip file from the desktop where you have it downloaded
7. Click on Install Now and then Activate to install the Theme