FTP Upload: Unzip the "huge-theme.zip" file and upload the contents into the /wp-content/themes folder on your server.
Wordpress Upload: Navigate to Appearance > Add New Themes > Upload. Go to browser, and select the zipped theme folder. Hit "Install Now" and the theme will be uploaded and installed.
Once the theme is uploaded, you need to activate it. Go to Appearance > Themes and activate your chosen theme.
Krown Portfolio - this is the plugin which activates the portfolio & gallery custom post types. It doesn't require any setup, just installation and activation, for the theme to have portfolios / galleries.
Krown Shortcodes - this is the shortcodes generator. If you want awesome shortcodes (columns, buttons, accordions, etc.) like in the preview, this is what you'll need to use. You are also free to use this plugin in absolutely any other themes you may wish.
oAuth Twitter Feed for Developers - this isn't a critical plugin, but it is needed if you want to use the twitter widget anywhere in your website. More about how to work with it later on.
If you do not see the notice to install these plugins or miss it somehow, you can go to Appearance > Install Plugins and you'll see the full list there.
There is an xml import file in the download ("huge-import.xml"), which can be used to achieve a near example of the online demo. Please note that the images which you see online will not be available when you do the import, since they're copyrighted.
This is a great starting point for your website, as you'll be able to delete everything at any time and only keep what you need, that start from there!
To use it, go to Tools > Import > WordPress and upload the xml file, choose to import everything, hit the button and wait.
Please note that this import is not perfect and it might fail sometimes, but it's a good solution if you can't or don't know where to get started.
Read this troubleshooting guide if you encounter any issues.