Are you talking about the picture of your bridge officer? You have to go to the tailor and change their appearance.
If you are talking about their powers/abilities, then you need to train them to a different ability at the bridge officer trainer (power store) at earth space dock. When you beam to ESD, head out the door to your right. Go north (up on the map). Go past the shipyard. The next section will have some NPCs on your left. One of them is a power trainer.