Dell Dimension 9100 - Manual (Page 79)

Removing and Installing Parts
79
Removing a PCI Express Card
1 Follow the procedures in "Before You Begin" on page 55.
2 Remove the computer cover (see page 60).
3 If present on your computer, rotate the lever on the chassis wall upward.
card retention
door
release tabs (2)
filler bracket
alignment guide
alignment bar
*lever on chassis wall
*may not be present on all computers