You will have to remove several screws and a couple of cables on the bottom of the ZG5 to remove or replace the wireless card.
Turn the netbook upside down with the battery at the top, away from you.
Unlock the battery by sliding the switch located near the left hinge to the left "unlocked" position.
Slide the latch located on the opposite hinge from the lock while pushing the battery up.
Gently loosen the two Phillips #0 screws in the small panel that covers the wireless card.
Lift up the panel and remove it from the case.
Disconnect the two antenna cables from the left side of the wireless card.
Remove the single 3.9 mm Phillips #1 screw from the bottom left of the wireless card.
Gently lift up the left side of the wireless card and slide the card out of its socket.