The Anniversary Upgrade includes pre-existing and new Creation Club content like quests, dungeons, bosses, weapons, spells, and more. With Creations, there is a lot more to discover. You must own Skyrim Special Edition to access this content.

Go to: http://store.steampowered.com/ and download STEAM client Click "Install Steam" (from the upper right corner) Install and start application, login with your Account name and Password (create one if you don't have). Please follow these instructions to activate a new retail purchase on Steam: Launch Steam and log into your Steam account. Click the Games Menu. Choose Activate a Product on Steam... Follow the onscreen instructions to complete the process. After successful code verification go to the "LIBRARY" tab and start downloading.