You can install the theme in two ways: through WordPress, or via FTP. The eduka.zip file is the Installable WordPress Theme and what you need to use to get the theme installed. Click here for the WordPress method, and here for the FTP method.
But first, you need to download the Eduka files from your ThemeForest account. Navigate to your downloads tab on ThemeForest and find Eduka. Click the download button to see the two options and download the Installable WordPress Theme.
Important previous information
Eduka Theme´s styles are not compiled as in the most of WordPress themes. This means the file style.css is empty. Eduka use LESS, a CSS language programming that allow the use of variables, arithmetic operations functions, etc, to accelerate and enrich the styles of the web.
CSS can´t be replaced by LESS, because its not recognized by browsers. This is the reason to process these files and get the final style.css sheet fully functional and compatible.
Then, as I mentioned before, CSS files are not compiled, and this the reason why after the first install the core of Eduka will redirect you to Eduka > Theme Panel and the stylesheets will be compiled in the directory
wp-content/uploads/sites/xx/eduka/css/ if you’re in a WordPress Multisite.