1.See you on http://uplay.ubi.com/
2.Click "Download Uplay"
3.Once the client is installed and has started, log in with your username / password (create one if needed).
4.Once logged in, click the key icon "Activate a product", or on the small options icon in the top right corner.
5.Select "Activate a product..."
6.A window will prompt you to enter the code you purchased on Instant Gaming.
7.Uplay will authenticate your code after a few minutes.
8.The game is now visible in your list.
9.Click it to start the download.
If you require more specific help, or if you have any questions, don't hesitate to Contact us.