How to loose weight fast...for a 16 year old guy?

I'm 16 and weigh 206. I'm not like fat, just big, but i want to change the fat to muscle. What do i need to do to burn the fat as fast as possible, and gain muscle. I have a whole gym thing in the basement, which i use every once in a while, but tomorrows sunday, and when monday rolls around i want to change my ways, and get the fat gone, junior year is coming fast, and i want to change. I will do what it takes, so please chime in with any advice. Workout plan, what to eat, what to not eat, anything! Thanks guys i really appreciate it. Oh, and p.s. its not to impress anyone, I'm just sick of being how i am.