Thanks to Sacah who pioneered this discovery and has graciously posted a zip file to make installing/enabling the console so much easier.
- Step 1: Download gui.zip from either of the locations below
- Step 2: Unzip the downloaded zip file to your %steamapps%\common\dungeon siege iii\data folder. My full path is C:\Program Files (x86)\Steam\steamapps\common\dungeon siege iii\data. Once it unzips you'll see a gui folder with the help_topics.scn and game.gui files. The game.gui is for a game with the DLC.
And you are done! Yes, that's right... it is that easy. If you wish to do it the manual (and more complicated) way feel free to follow the FULL instructions on sacah's website: