Extract and copy the files from the archive you have downloaded from CodeCanyon to your server or local server.
Create a database then edit config/database.php to set the database connection details.
In your browser go to install.php to install the database tables and create a default admin user. This will install the following tables: comments, comment_votes, options and users. (If you want to run the installer again an override the tables, go to install.php?force).
The default user is created with these credentials: admin / admin and you can access the admin at /admin.
Warning: After installation make sure you delete the install.php file!.