Dell Dimension 4550 - Manual (Page 87)

Adding Parts 87
6 Press the tab on the card retention arm and raise the retention arm.
7 If you are installing a new card, remove the filler bracket to create a
card-slot opening. Then continue with step 9.
8 If you are replacing a card that is already installed in the computer,
remove the card (see page 90).
If necessary, disconnect any cables connected to the card. Grasp the
card by its top corners, and ease it out of its connector.
9 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.
card
edge
connector
card
connector
card retention arm
tab
filler bracket