Dell OptiPlex All-in-One Plus 7410 Owner's Manual page 46

Steps
1. Remove the two screws (M3x5) that secure the graphics-card assembly to the display-assembly base.
2. Slide and lift the graphics-card assembly off the display-assembly base.
3. Using the tab on the DGFX door, pry open and lift the DGFX door on the graphics-card shield to access the graphics-card
fan connector.
4. Disconnect the graphics-card fan from the graphics card.
46 Removing and installing Customer Replaceable Units (CRUs)