It is not an easy decision to take when it come to stoping gambling because gambling is very addictive so it takes a high disciplined person to stop this habit, you try to stop this by uninstalling some app you use for it if you play online and total avoidance of place or friends that you feel that contributes to you indulging in the act.
We sometimes say we want to stop gambling but we found out that the more we are attempting to stop the more we are getting more attrated to it, there are some decisions we need to take action on, it's not a thing we can just say by just mere words, we have to take a cognitive actions over it and the best way is to distance self from any gambling related platform or environment that could draw our individual personal interest back to it, we easily got attrated to what we often sees every time.
Another one I have used over the years against other things I was doing and felt the need to stop doing them since they could cause damage to my life was to reduce the time I spend doing such things. If I was doing it for up to an hour every day I reduced it to just 30 minutes three times in a week and from there lower the time more and in the process I'll look for more productive things to keep myself busy so that the thought of returning back does not come to my mind.
If such approach is taken towards gambling it could also prove effective, but I'd know cause like I said before I have not tried it directly on gambling but if the need ever arises for me to stop gambling totally I guess this will be one of the methods I'd try.