HP Compaq Elite 8300 All-in-One Maintenance & Service Manual page 93

14. Slide the system board toward the top of the computer (3), and then lift up the board from left
side to prevent interference between the side I/O bracket with the I/O ports on board.
Figure 7-66 Removing the system board (model 6300 shown)
To install the system board, reverse the removal procedures.
Replace the thermal pad below the system board.
System board 85