How I go thin? Iam very fat

DIET/EXERCISE. Daily exercise and a healthy diet with portion control will help you lose weight. There are a number of medically supervised weight loss center that you can enroll in to achieve your goal. Good luck.
Best to work w/a Dr. Depending on how obese you are, it is medically safer to have your doctor measure your baseline, so that s/he can advise you how much to lose per week/month taking into account your medical conditions, and your goals, and also monitor your exercise regimen, and review your diet and supplements. Go slowly at first, and then pick up the pace, as conditioning is important for sustained success!