Step 2 · Disconnect Water Supply Line
Locate the water supply line, which is the flexible hose connecting the shut-off valve to the toilet tank. At the point where it connects to the tank, there is a large coupling nut. Using an adjustable wrench or channel-lock pliers, grip this nut and turn it counter-clockwise to loosen and remove it from the fill valve's threaded shank. Have a small towel ready as a small amount of water may drip out.