Common sense and time. It takes time to lose the weight. I lost 110 pounds. It took a year and a half. It wasn't hard at all once I set about doing it. I ate low fat-low carb-low calorie diet. I have since moderated somewhat and have many days where I 'cheat'.
The other thing that is mandatory is exercise. I walk 8 miles a day, 5 days a week. It works, folks.
That's it -- the exercise is the key. Burning 4,000 calories in a 2.5-hour hockey game a couple of days a week doesn't hurt. LOL.