What Fil said. Now here is my opinion on how to achieve that...
CARDIO: Do 3 or 4 days of cardio for 30-45 minutes per day. When you do your cardio, keep your heart rate up. Do you cardio via running, elliptical, swimming, etc.
NUTRITION: Eat 6 - 8 smaller, healthier meals every day. Remove trans fatty acids and shoot for 50-60 % carbs / 20-30% fats / 15-25% protein for your daily intake. Measure your weight and fat % weekly and adjust your diet accordingly.
WATER: Drink 1 - 1.5 gallons of water EVERY day. And, I should say that you shouldn't do this at one sitting. It is best to think of it as 8oz. no more often than 30 minutes (unless you are working out).
Decide on your outcome, design your plan, set goals, and follow through!
We will be with you all the way!
Good luck,
Rip