How to Install a Premium WordPress Theme
Choosing a WordPress theme can be a daunting task given that as a Premium member, you have over 4,030 themes to choose from. However, with the application of filters, you can easily choose your preferred Theme.
Free WordPress themes are of high standards and pass the test for CSS, security, standard compliant code, support for standard WordPress features, privacy and quality HTML.
Premium WordPress are preferred by many due to their uniqueness, support through WordPress forums on queries and, advanced futures and functionalities.
The assumption here is that you are already using a Free Version and wish to upgrade to a Premium version.
After you have logged on to your WordPress Dashboard, go to Appearance => Themes. Then click on Customize.