How do you unlock other factions in Medieval Total War 2

Go to the Medieval II:Total War folder and find \data\world\maps\campaign\imperial_campaign from the top of the window. Once you are there, find the file descr_strat. Open it with a text editor (Word, or somthing like that). Cut and Paste the 'unlockable' section into the 'playable' section and save the file. Launch the game and you should have every faction available. Make sure to backup all those files you are going to change so if you mess up, you don't have to reinstall the game.