1) Go up to her and start a conversation.
2) Ask her if she wants to hang out sometime.
3) WHIP OUT MY PENIS!
4) BE SURE TO NOT DO NUMBER 3!!!!
5) Flirt with her like I would with any other girl.
i kinda push it on her if she seems a little interested but other then that... most of the time just let her be or slowly catch her interest and open her shell up if she's worth the time.