Next you need to mount your motherboard into the case using the included screws that came with the case and a Phillips headed screwdriver.
Gently place the board inside the case making sure the holes lineup so you can put the screws through.
Next secure the motherboard by screwing in the mounting screws provided with your case. Remember right tightens the screws and left loosens them. Additional washers are no longer needed as today's motherboards provide adequate space around the mounting holes for a ground free connection.