Removing the Top Plate Assembly
1.Press the latch in, and turn over the core so the power button faces up.
2.Remove the four corner screws that secure the top plate to the four vertical posts.
3.Remove the four screws on the two sides. (The two screws that align with the vertical plates are much longer than the other screws.) (Figure 4)
Figure 4
Power Mac G4 Cube Optical Drive - 4