Optiplex GX 520
In the specifications that exist in the Dell Computer documentation:


Small desktop (SD):

PCI:
connectors
Two low profile
Connector size
120-pin
Connector data width (maximum)
32-bit
PCI Express: (optional)
connector
Two medium-profile connectors

there is an option to incorporate PCI Express Video Card to this model GX 520.
Someone could tell me how to incorporate this option and what material is needed?
Greetings.