Need some help installing a video card.?

Okay, so I decided to install a new video card on my Dell Inspiron 531S. After going through a normal size and a low-profile one, none of which fit, I got a Radeon B2 256 HD2600 XT from Dell. It came with a normal size metal thing on the side of it that come out of the computer and a very small one. How do I take the big metal thing off and put the small one on?