1.   Again, you can use the old threshold as a guide or you can use a contour guide to copy the profile of the stop molding and jambs.

2.   For instance, I recently designed some picture shelves with a combination of crown, base and stop molding.

3.   If the molding has been painted over, use a stiff putty knife to cut the paint seam between the stop molding and the door casing.

4.   Insert the knife between the stop molding and the jamb and gently pry the molding loose.

5.   Next attach metal-reinforced felt strips to the exterior side of the stop molding.

6.   The distance between the center of the track and the stop molding should be half the thickness of the door plus an eighth inch.

7.   The stop molding on older windows is apt to be dry and inflexible, so lift carefully at the nail locations to avoid breaking it.

8.   Then use a hammer and block of wood, as shown in the drawing, to slam the block against the edge of the stop molding.

9.   To free the sashes, use a utility knife to cut the paint film around the edges of the stop molding adjacent to the sash.

10.   Unlike the stop molding, which is nailed to the surface of the frame, the parting strip is inset into a groove in the window frame.