Get the installation link from our latest release notes. (For sandboxes make sure the link starts with "https://test.salesforce.com..." otherwise replace the "https://login.salesforce.com..." with it.)
Install the ADvendio Managed Package as described here under Section "2.2 Install the new Package".
Run the Ad Specs & Rates Manager or Inventory & Rates Manager to create Products.
Add the Remote Site to use the Booking Calendar described here.