Well, to be honest, it is actually very possible for a gambler to quit gambling slowly and end up with a positive result, but this I believe have to everything to do with how deep the gambler is addicted to gambling.
For someone who is not all that deep in their addiction to gambling, quiting can be quite simple, like just reducing the amount of time spent on gambling, and then spending more time on other activities that could help the addicted gambler think less of or about gambling. The gambler could decide to find a new job that keeps him or her extremely busy all day, and very tired and only want to just lay down and sleep the very moment he or she gets home, and the next morning, he or she is up again and off to the same work, coming back again in the evening feeling same way like the previous day.

Trust me, if an average gambling addict will engage themselves in such as I explained above for like a month or two to three months max, he or she may come out of his or her gambling addiction, and may not even remember anymore that gambling exists.