How can I lose this weight?

I am 15 years old, 6' 3" and weigh 237lbs with a body fat percentage of 27% and I want to lose as much weight as possible over the summer. I do not drink soda and drink atleast a gallon of water a day with some tea and milk during breakfast and dinner. I take vitamin c, specifically 1000mg of it a day for my immune system and blood, and a flaxseed pill which I believe had something to do with my fibrosis of the liver which I believe is no more. I eat a normal breakfast (cereal, milk, bagels, toast, fruits etc.) I have healthy lunches usually (soup, salads, fruit, light sandwiches, etc...) and my family typically gives me healthy dinners which are broiled grilled or steamed when it comes to it. Chicken and broccoli, fish and rice, dishes that are natural yet flavored by peppers and such. That should about cover any information needed. My question is, how do I lose this weight? I mean my ideal goal would be to lose every percentage of fat but what do I do? Please someone just give me a routine or something to follow any information. I have nothing wrong with me and my doctor says I'm healthy. I just wish to lose this weight.