Remove Old Flush Valve

What happens here

Locate the flush valve assembly, which is secured by a large nut from the underside of the tank. Before tackling the main nut, push the three small rubber gaskets on the flush valve's arms out of the way to gain better access. Then, using large channel locks or groove-joint pliers, grip the large nut and twist it counter-clockwise to remove it. Be prepared for some residual water as you remove the flush valve. Wear gloves to avoid contact with dirty water and grime. Once the nut is removed, the entire flush valve assembly, including the badly deteriorated red gasket, can be pulled out from the inside of the tank.

Goal: Extract the worn-out flush valve assembly.