How to lose 25kgs in 1 year?

I am 14 years old. I weigh 88kgs. I am 5 feet 10 inches. I want to loose 25kgs in 1 year and also want to increase my height. Please suggest me a good routine (sleep, workout, food, everything). I can only spare 1.5 to 2 hrs daily for the workout as I have to study for my ICSE exams... I can join a gym and do what ever you may suggest. Please guide me in the correct direction. Also, my obesity is not hereditary. Thanks in advance....