8.Reach back underneath the subassembly and disconnect the two power supply cables connected to the right side of the main system board, as shown below. Pull each of the connectors straight up; do not pull only on the cables.
power supply cables
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9.Lift the entire subassembly out of the computer and carefully place it on your work surface.
If you are installing a drive, follow the instructions under “Installing a Disk Drive in the Horizontal Position” on the next page.
If you are removing a drive, see “Removing a Disk Drive From the Horizontal Position” on page