Memory, CD or DVD Drive, Modem, and Mini PCI Card: Dell Inspiron 1100, 5100, and 5150 Service Manual
Modem
Removing the Modem
CAUTION: Before working inside your Dell™ computer, read the safety instructions in your Owner's Manual.
CAUTION: To prevent static damage to components inside your computer, discharge static electricity from your body before you touch any of your computer's electronic components. You can do so by touching an unpainted metal surface.
1.Follow the instructions in "Preparing to Work Inside the Computer."
2.Turn the computer over, loosen the captive screw (labeled "circle C") in the modem/Mini PCI card cover, and lift the cover away from the computer.
1 
captive screw