OK, the instructions below are for the old edition of the PS2. There are pads (I think there is six in total) on the bottom of it. To lift these pads off, jam a small screwdriver into the side and prise off the pads. Under this you will find 6 screws. Undo these and gently lift away the roof of the PS2. Tearing at it will not help, as there is a silver cable from the ON button and to the machine. Undo this and your stumped (like what I did). The machine will get hot, but will not turn on(?)
P.S. As Mr. X rightfully said, it is a count of vandalism when you use it in the wrong sense.
Chad Bronson, December 2006