First of all, thank you for purchasing our product.
Please be aware that the Starter Blog Pro version is an add-on plugin, which adds the additional pro features to the Starter Blog theme.
Therefore you have to install the Pro version as a plugin, not as a theme.
How to Install WordPress Plugins via Dashboard
First, you need to download the plugin from the source (which will be a zip file). Next, you need to go to WordPress admin area and visit Plugins » Add New page.
After that, click on the ‘Upload Plugin’ button on top of the page.
This will reveal the plugin upload form. Here you need to click on the ‘Choose File’ button and select the starter-blog-pro.zip file you downloaded earlier to your computer.
After you have selected the file, you need to click on the ‘Install Now’ button.
WordPress will now upload the plugin file from your computer and install it for you. You will see a success message like this after the installation is finished.
Once installed, you need to click on the Activate Plugin link to start using the plugin.
You would have to configure the settings to fit your needs.