1. Open the "DefaultEngine.ini" file in the "Alice Madness Returns / Game / Alice2 / Alice Game / Config" with the text editor.
2. the very bottom is the entry:
GIsSpecialPCEdition = FALSE
3. Change "FALSE" to "TRUE"
4. Save the change
The game now has all the DLC content unlocked that are already included on the media, and console gamers have to purchase only.