Is it possible to lose armpit fat, PLEASE HELP?

I'm a 15 year old girl. I've always had armpit fat (I used to be overweight). I still carry a little extra weight and am looking to drop 5-10 lbs. I CAN'T STAND MY ARMPIT FAT. I cannot wear anything strapless because it looks bad. This is not created from clothes; even when I have nothing on, the armpit fat is completely there. People say diet and exercise, others say its impossible except for lipo (I'm a teen I can't do that), some say arm exercises. What can I specifically do to get rid of this? I know spot training is impossible, and I don't want to lose my boobs.