How to ask her out?

Ok, here we go, you need to become her friend but not too good of a friend because then she will just think of you as a brother....Do things with her, ask her to go to the movies or hang out sometime. See if she wants to study with you. I was a girl in high school once and guys are always shy, I know in my case I wanted a guy who was smart and knew how to have a good time but also when it came down to it, knew also how to be serious....As for your friend, he will be upset and he will get over it. there are plenty of fish in the ocean. also you need to think "Is losing my friend over a girl worth it?"