1.Download Origin app: Origin
2.After the Download is complete run it and install it.
3.Once Origin is installed, open it and log in with your username / password (create one if needed).
4.Once logged-in click "Once logged in, click in the Origin Menu in the top right corner."
5.Select "Redeem Product Code"
6.A new window will ask you to enter the code that you purchased on GK4A.
7.Origin will now authenticate your code after a few seconds.
9.After the activation is complete the game will be visible in your games list.
10.Click it to start the download.
If you require more specific help, or if you have any questions, don't hesitate to to Contact us by Chat or normal contact form.