It is not a matter of replacing. CIA must change the attitude they have showed after WW2, meddling with other countries, removing governments and looking for conflicts. They should try to leave the cold war behind, as Trump and Putin seem willing to do.
@Pfuzylogic: I don't think neither CIA or KGB should be deactivated. They can be useful to fight terrorism, which is now the biggest global threat. But CIA remains stuck in the 'evil Russians' rethoric.