If there are no visible screws on the outside of the player it most likely has snap lock fasteners. You will have to gently use a sharp object to force the player open. If you start at a corner and gently move around the player you will find the points of connection. Be warned though that you could damage your case or the snap locks trying to open it.
If you have been ripped off with a hacked player by a seller submit a report to www.ic3.gov