Go to your game library, right click the game and go to Manage -> Browse Local Files
Open the steam_appid.txt file and change the steam id to 635580
Save the file, right click it, go to properties and set it as READ ONLY *important*
Then boot up the game, hit start, and then quit the game.
The achievement should pop.
After, you'll probably want to delete the steam_appid.txt file and go to the game properties in steam library and click "verify integrity of files" just to be safe (it will restore all original files).