Crew Expendable DLC: The original crew are reunited on the Nostromo. With Brett and Kane dead, team up with Ash and Lambert to stop the bloodshed before it’s too late. Take control of Dallas, Parker or Ellen Ripley to hunt down the Alien and overcome the terror that is tracking you down!
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