The first step is to mow your grass short, leaving only about 50% of the leaf blade. Next, reduce watering significantly for 5 days. This stresses the ryegrass and allows the hybrid to flourish. Finally, fertilize with 21-0-0 analysis or a fertilizer with a similar rate of ammonium sulfate and return to a regular watering and mowing schedule. Be sure to rake the ryegrass off as it dies out so that the underlying hybrid Bermuda gets plenty of sunshine and water.