HP DM4 - Manual (Page 50)

3. Remove the two Phillips M2.0×4.0 screws (2) that secure the WLAN module to the computer.
(The edge of the module opposite the slot rises away from the computer.)
4. Remove the WLAN module (3) by pulling it away from the slot at an angle.
CAUTION: To prevent an unresponsive system, replace the wireless module only with a
wireless module authorized for use in the computer by the governmental agency that regulates
wireless devices in your country or region. If you replace the module and then receive a warning
message, remove the module to restore computer functionality, and then contact technical
support through Help and Support.
NOTE: WLAN modules are designed with a notch (4) to prevent incorrect insertion into the
WLAN module slot.
Reverse this procedure to install a WLAN module.
42 Chapter 4 Removal and replacement procedures