At the 'Options' menu go to 'Gameplay Settings' and select 'Enter Cheats'. Then using your Xbox 360 controller enter the following codes to unlock the corresponding outfit. If you have entered the code correctly you will hear the sound of a chime and get a prompt.
Unlock Angel's DC1 Outfit: Enter Y, Right, Left, Up, X, X, Down, Y
Unlock Emilia's Classic Dance Central Outfit: Enter Left, Left, Up, Right, Right, X, Down, Y
Unlock Miss Aubrey's Dance Central Outfit: Enter Left, Down, X, X, Down, Right
Unlock Taye's Classic Outfit: Enter Up, Left, Y, X, Left, Up, X, Y