HP ProLiant ML110 Gen9 User Manual page 56

Open the PCIe slot cover retainer and remove the slot 1 blank.
9.
Retain the blank for future use.
10.
Remove the secured screw from the system board.
11.
Install the GPU with the supporting holder in slot 1:
12.
Secure the captive screw of the supporting holder to the system board.
a.
Hardware options installation 56