You can upload the un-zipped file to the correct folder on your site if you have FTP log in details.
- Download your purchased Pro theme in your computer. It will be downloaded in the form of a compressed .zip file.
- Extract the downloaded folder to your computer.
- Use FTP details to login to your site and upload the theme folder to the wp-content/themes/folder.
- Go to: Appearance › Themes to Activate the theme.