check this video out for help, fast forward to mark 20 min for the stuff needed to pass bar ref
https://www.youtube.com/watch?v=W6TI5-2R2_Y&index=8&list=PLXDWN8TfqFlTzBS-gh7Vpi5CGQ4_TMBTJ
https://www.youtube.com/watch?v=W6TI5-2R2_Y&index=8&list=PLXDWN8TfqFlTzBS-gh7Vpi5CGQ4_TMBTJ