Launch Origin and log in to your account.
Click one the Origin logo in the upper left corner of the main window, then click one the Redeem Product Code option.
Enter the code you have received and enjoy.
Launch Steam and login to your account.
Go to Games and then click Activate a Product on Steam.
Enter the code you have received.
The game has been activated and added to your Steam library. You can play now!
Run Uplay. Login with your login and password (or create new account if you are new user).
Click on Settings icon in the upper right corner and select Activate product.
Enter the code you have received and click OK.
The code has been redeemed and the game activated. Have a fun!
Enter www.battle.net website.
Login with your account.
Click Account on the top of the page.
Click Games and codes in menu.
From menu select first position: Add a Game Key.
Enter your code and click Redeem Code (You may have to select game account, to which code is to be assigned).
Go to https://socialclub.rockstargames.com/signup and log into your Rockstar Games Social Club account. If you don't have a valid account yet, join the Club!
Enter your code on the Social Club Activation page.
Download your game and enjoy!