Push a screw into the grill until just the tip pokes out, rotate the grill around until you feel it hit the screw hole, tighten a little with your fingers to be sure. Loosely tighten all the screws until you get them all in. Then tighten them all down.
My opinions are the result of years of rational, objective analysis. I analyze all factors before making a choice. I update my opinions to include new facts. Fallacies? No?