Dell Precision T7400 (Late 2007) - Manual (Page 211)

Adding and Replacing Parts 211
7 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 bracket.
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.
1 release tab 2 card retainer
1
2