You need aerobic exercise, meaning something that gets your heart rate up like running. That kind of exercise burns fat. For the period of time you're looking at try 45 minutes a day of something that really wears you out.
As for food, Atkins works well for the short run as said by meweiss182, but don't stay on it for a long time because it can cause kidney and liver problems. For the most part just try to take in less fat. Don't eat less, because that will slow down your metabolism. It's not how much you eat, it's what you eat. Eat fruits and vegetables opposed to candy. Cut out caffeine period. No cokes at all. Try to get under 20 grams of fat per meal, or around there anyway.