Just go to Admin Panel > Frizty Options and go to Layout Settings tab. Here you will find Demo Content Setup section like this:

Just click on the Demo Content Setup button and read the instructions:

You can select which demo you like to setup. Like Default, Classic, Elegant etc. Just select it from dropdown as described below:

Now click on the I agree, continue demo content setup button and the installation process will start (this process may take 5 or 10 minutes depends on your server performance):

When finished, you will see message as given below. Also this will refresh the page to apply the new changes so the below message will be seen for some seconds only.

All done. Now your site will be same as our demo site.