First fill the tank with water, formula and BOOST. Follow the fill lines for the right amount of water and formula. For large messes use the BISSELL Boost. Replace the tank on the machine by pressing it firmly into the machine. Select your desired tool and click it into place on the hose. Push the power button under the handle to ensure it turns on. Hold the tool over the stain and push the trigger on the hose to saturate the stain. Use back and forth motion to clean the stain. Stop holding the trigger to continue sucking up the dirty water.