Harmful social norms often persist despite legal and economic penalties. Can the abandonment of a harmful norm be facilitated by the presence of a \mildly harmful" alternative that may act as a stepping stone in the medium run? Or will this become a new norm? We propose a dynamic, game-theoretic model and derive necessary and sufficient conditions for a stepping stone transition. Using original data, we apply the model to female genital cutting in Somalia, which has transitioned from an invasive to a milder form of cutting. The framework is general and shows that intermediate actions may have unintended consequences.