My friend is a major nerd, but wants to change.?

This is always hard because you will be the one responsible for that. One thing that really makes everyone change is to wear the hair down and lose the glasses and shoulders rolled back and look at everyone right on the eyes when talking to them with this posture and sound as confident as possible but speak little. This is already so much but it will change her immediately. She need to practice this with you and other friends a lot. The clothes I really believe you know them. Good luck!