Step 3 · Disconnect and Remove Old Supply Line

This is the step people usually slow down on. Go finger-tight first, then a quarter turn. No rush — replay the clip whenever it helps.

With your bucket and towel in place, start by unscrewing the coupling nut that connects the supply line to the plastic threads of the toilet's fill valve (the bottom of the tank). This is typically a plastic nut and can often be loosened by hand. If it's tight, use an adjustable wrench or pliers gently. Next, use the adjustable wrench to loosen and unscrew the nut connecting the supply line to the shut-off valve on the wall. Once both ends are disconnected, remove the old supply line.