Push the Wireless LAN card into its slot and rotate it down and secure it with the two retaining screws.
Replace the two antenna leads.
The black antenna goes to the connector nearest the LCD, the grey antenna goes to the connector nearest the front. (Some WLAN cards may have a third lead which will connect to the white antenna.)
Replace the cover and tighten the captive screw.
Replace the battery by sliding it into its slot and pressing it into place.