6.Turn the computer around, open the I/O panel cover, and remove standoff nuts ST1, ST2, ST3, ST4, ST5, ST6, ST7, and ST8.
Use a 3/16 nut driver to remove standoff nuts ST1 through ST6 and a 7/32 nut driver for ST7 and ST8.
7.Remove cover alignment screws S16 and S17.
8.Remove main board screws S18, S19, S20, and ST9.
S18 has a corner brace that must be removed. ST9 is a standoff screw and requires a 5/32 nut driver.
9.Bend the options bay wall (see Figure 4-32).
Press gently on the ends of the wall just enough to free the option bay con- nectors on the main board. Be careful not to bend the wall in the middle. When reinstalling the main board, bend the wall back to the vertical position.
10.Remove the main board.
Lift the end of the board nearest the front of the computer, and pull the board up and out of the computer.