How to lose 30 pounds over the course of a summer (thats about 2 and a half months for me)?

Well, I am not very healthy of course. I am 14 and am 5'9 and weigh roughly around 182-189 and I was really just wondering how to get rid of the weight, I am a boy by the way, and I am starting high school after this summer and am really trying to go through a big change so that i would look different than I did in middle school and of course this is all for health, so all I would like to know is a good diet plan and exorcise plan also so that I can just get it over with and drop the weight, so please, I just need some serious answers and some solid experience would help tremendously also, thanks!