You can't unfortunately. I think this might have something to do with Roster fighters allowed to be taken through career. As well as being able to manipulate them for Ultimate Team. If you remember Undisputed, people had 255 OVR CAFs. This is a safe guard against something like that. Your best bet is to make your CAFs by going to "Customize" then "Create Fighter". Make your CAF there and import them into career or Ultimate Team. Then you can adjust your stats and moves to match the career mode or Ultimate Team CAF.
