More in Windows Walls and Doors
Cut the old threshold in two with a hacksaw and dislodge it with a pry bar. Once it's been removed, clean the area thoroughly.
Carefully measure the opening for the new threshold and cut to fit. Next, lay a bead of caulk along what will be the back edge of the threshold.
Position the new threshold (Image 1), making sure the angle is sloping slightly away from your home to avoid water buildup (Image 2).