Fitness help please ? :) five star rating for best answer?

so i'm 16 5'2 and 160 pounds. my stomachs not really big but my arms are humongous and my hips butt and thighs but that parts okay with me . what i really would like to know is how to tone up my arms before summer or at least before summers over . we have 2 weeks left of school . so how can i tone up my arms and stomach in a month , please help me :) thanks