Disconnect all wires connected to the system board.
Remove the 5 screws that attach the system board to the chassis.
Slide the system board toward the front of the machine, and lift out from the back, as shown. When installing a system board, lower into place and slide toward back of machine to lock in place.
Note: When replacing a system board, make sure that you take the existing I/O shield off the new system board before doing so, as the I/O shield is built into the chassis. Replace the hex nuts once the I/O shield is removed.