Lenovo 10A4 Hardware Maintenance Manual page 198

Figure 162. Removing the eight screws that secure the system board
9. Slide the system board to the front of the computer and then carefully lift the system board out of the
chassis.
10. Remove the microprocessor from the failing system board and install it on the new system board. See
"Replacing the microprocessor" on page 186.
11. Install the new system board into the chassis by aligning the eight screw holes in the new system board
with the corresponding mounting studs on the chassis. Then, install the eight screws to secure the
system board by following the sequence shown in the following illustration.
190
ThinkCentre M83 and M93/p Hardware Maintenance Manual