Just sit next to her in class, and if you were suppose to do homework or study or anything like that, just ask a general question about something like you don't understand it; hopefully she will explain it to you and this should be your door to ice break once she gets through it, you could lead to just other general questions like what her name is and what she is studying and what she plans to do with her life. It usually worked for me...one time I had a girl back in my dorm and clothes on the floor before the day was out.
Everything you need to know is in this video.