answer:That much weight in that short of a time period would be unhealthy. Usually the upper end of healthy weight loss is one or two pounds a week. If you try to lose that much weight, most of it will come from muscle degrading, which i’m sure you don’t want. Also, you’ll gain it back again very easily. As far as how to do it, eat less, exercise more. Sparkpeople.com has a good calorie tracker for food, and it’s free once you sign up.