Dell Precision T5400 (Late 2007) - Manual (Page 197)

Adding and Replacing Parts 197
6 If you are replacing a card that is already installed in the computer, remove
the card:
a If necessary, disconnect any cables connected to the card.
b If the card is full-length, press the release tab on the end of the
alignment guides on the fan case.
c If the connector has a release tab, press the release tab as you grasp the
card by its top corners, and ease it out of its connector.
7 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.
CAUTION: Some network adapters automatically start the computer when they
are connected to a network. To guard against electrical shock, be sure to unplug
your computer from its electrical outlet before installing any cards.
8 If the card is full-length, align it between the plastic card guides on the
card fan case.
9 Position the card so that it is aligned with the slot and the securing tab (if
present) is aligned with the securing slot.
10 Place the card in the connector and press down firmly. Ensure that the card
is fully seated in the slot
If there is a release tab on the card slot, pull the release tab.