Many game manufacturers such as Nintendo and Xbox use a combination of Phillips-head and tri-wing head screws to close the system's case. They do this to deter people from opening up their game systems and possibly damaging the circuitry. If you work on your own game systems or just wish to change your case, you must remove these screws. The tri-wing screw is similar to a Phillips-head except that it only has three slots instead of four. The best way to remove these screws is to purchase a screwdriver specially designed for the tri-wing.
Purchase a tri-wing screwdriver from a electronics repair shop or online. Alternatively, find a small flat-head screwdriver that fits into one of the slots on the tr-wing screw. If using a flat-head screwdriver, it only needs to fit enough that you get some "bite" without stripping the head.
Unplug your game set and turn it upside down over a towel. Locate the various screws that secure the case.
Press down slightly on the screw with the screwdriver and turn counterclockwise. Once you have the screw loose, let off the pressure while continuing to turn the screw. When using a flat-head screwdriver, you may have to hold the blade at an angle to get a good fit into one of the slots. The screwdriver tip will angle on one of the other slots enough that you can turn the screw.
Loosen all the tri-wing screws on the game case until all they do is spin. Turn the case over and gently tap the top of the case to release the screws.