How do I get rid of Bellyfat?

?....I'm 14, and i'm 5'9" i weigh....145lbs. I'm not really fat, i just have a little bit of belly fat, that i'm not very fond of. What do I need to do to get it off. I do kickboxing which blasts calories, but is it doing anything for my abs?? Do i need to just do sit-ups. I have very strong abs, so that is no problem, but it's boring. What else can I do???