it's a combination of eating habits and cardio. cardio 5 times a week sounds good, but it depends on how much and what you eat, you only burn a certain number of calories and if your diet isnt good enough (let's say you still eat way too many calories per day and too much fat, it wont make much of a difference)
you need to get that shit figured out. im sure there's plenty of books, articles on the net etc on the subject, or if youre real serious in making a difference get someone to check your eating habits, calculating how many calories you eat per day and all that stuff.
as for certain exercises, there's no such thing. good luck and think long term.