Helping a Friend

How do I assist a friend in overcoming a low self-esteem issue? It manifests as a need to prove himself with younger women. He’s sensitive and reasonable, but in this area he cannot see that he exploits and manipulates to get what he wants. I’ve suggested counseling. I’ve tried to talk to him of the truths I’ve learned, but he’s told me I’m too preachy, and he’s unable to hear them yet.