First things first is the willingness of the person to help himself, if that is already present the chance is high of curing itself, though if addiction is already deep then professional help and guidance from someone who you really trust will help in boosting your self-will to quit away, there are many factors that can really affect your decision making when trying to un-tie yourself into gambling, we do all understand addiction and it's not that easy to remove if you have it inside you.
It takes time and solid determination to help yourself, but it's always doable if you really believe that your changing pace will help you to solve your own mistake.
Well said Fredomago !!! Most people don't even believe that they have a gambling disorder because they feel that they are gaming within their limits. However, a close observation of their gambling activity will prove that they are suffering from gambling addiction. After acknowledging that they have a problem, the next step should be the willingness to break free from this addiction. With determination and self-control, gamblers can come out from addiction. Seeking the advice or help of concerned family members and friends could be of great help but sometimes they are limited because most of them lack the needed counselling skills.
But if you have tried and discovered that you need external help, then the services of a professional should be sought. Experienced addiction counsellors will come up with peculiar rehabilitation procedures that will be of great help. But all this assistance will be helpful only if the gambler is willing to change from this harmful gambling behaviour.