In the Civ4CivilizationInfos.xml file each civilization has 2 tags within their code, bPlayable and bAIPlayable. The first sets whether the civ can be played by the human player or not, and the second sets whether the civ can be played by the AI or not.
Change these tags to this:
Code:
<bPlayable>0</bPlayable>
<bAIPlayable>0</bAIPlayable>
That sets them to false, meaning they cannot be played in the game. I did this to all the original civs, making only Harbaal's fantasy civs playable.
Hopefully in his new version that he releases soon he will have this done already so we won't have to