1. Open the Uplay client and log in.*
2. Click on GAMES tab.
3. Click on the ACTIVATE PRODUCT button.
4. Enter your code in the "Activation Product" field.
5. Click OK at the bottom of the Uplay Product Activation page. This will activate the game on your Ubisoft account.
*If you are new to Uplay please download the client and create an account at HTTPS://ACCOUNT.UBISOFT.COM.