Dell Precision T7400 (Late 2007) - Manual (Page 209)

Adding and Replacing Parts 209
3 Press the tabs on either end of the card retention device and lift to remove
it from the computer.
4 Gently securing both graphics cards with one hand, remove the graphics
card bridge (if present) with your other hand by pulling it up and away
from the computer. Set it aside.
1 card retention device 2 tab
1
2