Dell Precision R5500 (Early 2011) - Manual (Page 56)

23. Position your thumb firmly over the processor socket-release lever. Release the lever from the locked position by
pushing down and pulling out from under the tab.
24. Rotate the lever 90 degrees upward until the processor is released from the socket. Rotate the processor shield
upward and remove it.
25. Carefully lift the processor out of the socket.
26. Repeat steps 21 to 25 for the second processor (if installed).
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