Step 3 · Open the Cleanout Plug
Position your body to the side of the cleanout plug, not directly in front of it. Fit a large pipe wrench or an adjustable wrench onto the square nut of the plug. Exert steady pressure to turn the plug counter-clockwise. It may be very tight due to age and corrosion. Be prepared for wastewater to begin seeping or flowing out as the threads loosen. Open it slowly, allowing the pressure to release gradually and the initial backup to drain into the bucket. Once the flow stops, you can fully remove the plug and set it aside.