The adapter card is much taller than a typical M.2 Wifi card so you'll lose access to the left M.2 NVMe slot. To remove the screw holding the Wifi card in place, you need a small wrench or a 5mm nut driver. If you have a M3x4 screw, use it to secure the adapter to the motherboard. Then put the Apple Wifi card into the adapter and screw it on with the provided screw. Finally, attach both Wifi antannas. You can keep the card in place by the tension of the antannas and the pressure of the top lid.