Eador is a universe made of countless shards of land drifting in the Great Nothing. Each of the shards is a little world unto itself, with geography and denizens of its own. The power over the shards is bitterly contested by Masters, the immortal beings mortals believe to be gods.
Open the Steam client, login and locate the Games tab on the top menu. Click this and then select “Activate a Product on Steam…”
Enter your unique code that's displayed on the 'Orders' page of CDKeys.com and follow the prompts to activate.
Your game is now viewable in the “Library” tab and is available to download/install when you’re ready. You can find additional support for the Steam client here: https://help.steampowered.com/en/wizard/HelpWithSteam