How do you exactly get buff if you're overweight?

Yes: Eat healthier, exercise more.

Diet/exercise: Diet and exercise are the only effective methods, but it's hard to get "buff" if you've been overweight because the skin has been stretched out and stays that way even if you lose weight and enlarge your muscles.

Diet and Exercise: Count your calories, mostly plant based diet but with a good protein source, eat 3 small meals a day, plenty of water, both aerobic exercise and resistance exercise. A trainer to start is often a great idea.