Measure the height of the kickplate. Select a vent cover that is 1 inch smaller in height and as wide as possible.
Turn the vent cover upside down and measure the outside dimensions of the installation frame. This frame will be inset from the outer edge of the cover by up to 1 inch on all sides. Transfer your measurement to the kickplate. Center the width and height. Draw the shape on the kickplate and check your measurements.
Cut 1/8-inch outside your lines using a small rotary cutting tool. Remove the cut out section.
Insert the vent cover into the hole. Screw the cover in place using screws and a screwdriver.