You should post this in questions and answers.
Beat the story mode and the option will be available.
Hey this Kyoshi, you may know me as annefranman52. JOIN TEAM ANNEFRANMAN!!! Best mates on here: BeN_b!, SCD, whippy, Lurch, ozzo, Daltoso, ILME, rc, Arbitor, ShadowGX, SuperDJ and Aeshma.