My son has a HUGE crush help!?

He thinks she is out of his "league" and that there is a boy who all of the girls "like like" i'm not so sure of this... any ways she doesn't even notice him and that whenever she's looking something embarrasing happens and is BFF's with this boy. so he wants to know how can he get her to at least like him (but better yet like liking him)while being "incognito" He is 9 and will be turning 10 in three or four months. Thanks!