Squeeze the two mounting spring wires together on each side of the grill. Use your thumb and forefinger to bring the wires of the spring together.
Insert the two wires from the spring into the slots inside the NuTone blower or exhaust housing. The slots look like two small hooks in the side wall of the housing, about an inch apart.
Push on the front of the grill to press it against the ceiling and secure it in the blower or exhaust housing.