Replacing hair when head rotates

I am a noob with a trial version of After Effects. I am trying to replace the hair of a person in a video with a png of large afro hair. I have been able use motion tracking and a null object to get the afro to stick to the head, but when the head rotates from straight ahead to a side view I'm not sure what to do. Is there a way to take a png of the afro and make it 3d and possibly use motion tracking with it? What is the best way to handle hair replacement when a head rotates? Thanks for any advice.