Remove Old Fill Valve

What happens here

First, unscrew the supply line that connects to the bottom of the fill valve. These connections are typically hand-tightened, but a wrench or pliers might be needed if it's too snug. Once the supply line is disconnected, use a pair of pliers (the presenter uses 10-inch Knipex Cobras, then switches to 6-inch for better access in tight spaces) to loosen the large nut on the underside of the toilet tank that secures the fill valve. Carefully remove this nut, then lift the old fill valve out of the tank.

Goal: Disconnect the water supply line and unfasten the old fill valve from the toilet tank.