Dell OptiPlex Small Form Factor 7010 Owner's Manual page 100

Steps
1. Align and lower the system board into the system until the stand-off points at the back of the system board align with those
on the chassis.
2. Replace the seven (#6-32) screws to secure the system board to the chassis.
3. Route and connect all the cables that you disconnected from the system board.
100 Wymontowywanie i instalowanie modułów wymienianych na miejscu (FRU)