Dell Precision 690 - Manual (Page 41)

3. Press the tabs on either end of the card retention device and lift to remove it from the computer.
4. Press down the tab on the top of the card retainer at the appropriate card slot and pivot the card retainer back through the chassis wall.
5. If you are replacing a card, see Removing a PCI Express Graphics Card from a Dual Configuration .
6. Prepare the card for installation.
See the documentation that came with the card for information on configuring the card, making internal connections, or otherwise customizing it for your
computer.
7. If the card is full-length, align it between the plastic card guides on the card fan.
8. Position the card so that it is aligned with the slot and the securing tab (if present) is aligned with the securing slot.
1 card retention device
2 tab
1 release tab
2 card retainer
1 PCI Express x16 card