First thing todo using sub-classes is always just how to divert them. Somewhat disappointingly, it takes completing the whole single-player story for to the purpose of downloading them. After completing the key Story, you are certain to find yourself a assignment to scavenge yet another Memory Board. This assignment specifically includes two "post game" assignments, one that requires one to dig the own base, and also one other to save a survivor. After that you'll be made to input the Skill Trainer to check at your four fresh sub-class choices.