you can download the Database of the demo site with sample files here:

Change the folder /application/files in your installation with the folder in the zipfile and replace the database with the included demo DB.
You can login using these credentials: 
username: admin
Password: admin (Do not forget to change it immediately!) 

Installation instructions

connect to the marketplace from your dashboard and install the package

Manual installation:

  1. Unzip this file in your site's packages/ directory.
  2. Login to your site as an administrator.
  3. Find the "Add Functionality" page in your dashboard.
  4. Find this package in the list of packages awaiting installation.Click the "install" button.