just stop it and don't touch it again
Yup, this is the simple and perfect answer. Stop playing and don't see gambling site anymore. But this is not easy for real gamblers. They don't have control over their emotions. So I think they can take help from family members and also they need some prescriptions from doctors. And more importantly they have to control on their minds otherwise staying out from gambling is not easy.
Absolutely he can easily say and do that one because i think he isn't a gambler who gets addicted to it. But if he can experience also what op experience i think he will also surely ask for any advice on how to stop
If a gambler is addicted, it is not easy to say no to things that he is addicted to, just like those drug addicts, its hard for them to turn away from their vice, sometimes they go to a rehabilitation center to be cured, same as in gambling, if you are addicted to it, rehabilitation would be needed or if you want to do it your self, you would need a good research and the support of your family.