Replacing the 2000 series WiFi dongle
Remove these 8 screws.
Remove these 6 screws.
With the bottom back cover already removed, remove the wingnut and ground wire.
Remove aux. USB plug (should be in in slot 2).
Remove the pendant cable from control enclosure (unscrew the little nut from the connector).
Carefully remove control enclosure.
Locate the WiFi dongle at the top of the PC.
Remove WiFi dongle.
Disconnect the cable form the dongle.
Connect the new dongle to the cable.
Plug the dongle back into the slot and reassemble the control in reverse of the disassemble.