Dell XPS 8500 (Early 2012) - Manual (Page 45)

3 Locate the PCI-Express x1 card on the system board.
See "System-Board Components" on page 21.
4 Disconnect any cables connected to the card, if applicable.
5 Grasp the card by its top corners, and ease it out of its connector.
1
2
1 PCI-Express x1 card slot 2 PCI-Express x1 card
PCI-Express x1 Card(s) 45