Measure a 6" section of the existing downspout at least 24" above the top of the preferred collection container. Slide the top portion of the Mystic TM , nesting it into the bottom reservoir and attach the hose to the outlet port. Cut out the measured section. To avoid possible damage to siding, place cardboard or protective material between the downspout and siding. Connect the hose to the collection container and enjoy the results of sustainable rainwater collection. Place the Mystic TM into the downspout section.