Dell Precision T3400 (Late 2007) - Manual (Page 165)

Adding and Replacing Parts
165
5 If necessary, disconnect any cables connected to the card. Grasp the card
by its top corners, and ease it out of its connector.
NOTE:
If you are removing the card permanently, install a filler bracket in the
empty card-slot opening.
NOTE:
Installing filler brackets over empty card-slot openings is necessary to
maintain FCC certification of the computer. The brackets also keep dust and
dirt out of your computer.
1 release tab 2 card retention cover
3 card retention door
3 1 2