step-1: When temptation comes to your mind go and take a bath and get out of your room.
step-2: Go to your favorite place alone or you can join your friends for hiking in your city but stay away from your friends who are always like to talk about girls, sex, new porn, etc.(bad talk)
step-3: You have to meditate regularly to take control of your mind so this is the important step, do yoga, and exercise along with it(optional), you can find more about meditation on youtube.
step-4: If you are an adult then you can find a partner for your self because masturbation is bad for health but sex with your partner is good for health. There are so many good reasons you can google it.
It is very true, but since he has a serious addiction to porn, what can also happen is that when he is with a woman, watching the porn movie again and doing to the woman everything they do there, is like trying to imitate him, when he was 17 -18 years ago I was doing that because I was addicted in the same way I did all those things and so the sexual energy is transformed into satisfaction for her and for you. The best part is that after they will look for you ..