Only time will clean you out. Exercise will help a little but you want to make sure you stop exercising 4-5 days before the test because those extra THC molecules you burn up when exercising end up in your urine. Eating low fat foods during the exercise period can help slightly as well as switcing over to high fat foods during the lazt time period. Drinking excessive water will not do it. Excess water on the day of the test can help you dilute your urine and pass but it will not clean you out. Consider home testing as well as subbing with clean urine.