[ Diet & Fitness ] Open Question : BODYBUILDER'S HELP!!!?

im a 5'9 200 lb 15 year old guy, i do not have an exact measurement but i think im at about 18-20% body fat. i have more muscle than the average 14 ear old so height to weight bmi tests don't work. i have been overweight for most of my life but in the last year i have done martial arts and weight lifting. i have gotten 5 inches taller this year and 50 lbs heavier and its not all fat. i want to lose about 30 lbs of fat and gain about 40 lbs of muscle. i want to look like Arnold in this pic http://www.arthurshall.com/x_bodybuilding.shtml i already have a big chest, 42 inches around not flexing. i want to become a bodybuilder later but for now i just want to be ready. my goal for this time next year is to get down to about 7% bf and 235 lbs. i don't just want to be big, i want to be really strong like andy haman. is it possible to do this, and more importantly how do i do this. and how do i start a bodybuilding career