To turn off Punkbuster your server must first be unranked.

Edit the code into your Startup.txt config.

This can be found here: Clanforge -> Your Server -> Edit Profile -> Config -> startup.txt from the drop down menu

Hit Save & Apply to apply the changes.

#Will the server be ranked true/false
vars.ranked "false"
#To password the server, must be unranked
vars.gamePassword "$$game_password$$"

#$$variables pull the password from the settings tab