In this example, we’ll grade from a size 42 at the waist to a size 44 at the hips. Only pieces 1 through 5 will need to be modified.
Trace the waistband pieces (#10 and #11) in your waist size (here 42). Trace the remaining pieces (single-sized).
For piece #5 (pants back), start by drawing a line perpendicular to the straight grain that goes through the crotch notch. Trace the pattern piece in size 44 (hip measurement) below this line, and in size 42 (wait measurement) at the upper edge of the piece. Using a curved ruler, draw a line between sizes 44 and 42 along the side seam. Draw a straight line from size 44 to 42 at the crotch.
Mark point A where the waist line and side meet. Draw a line parallel to the straight grain going through point A. Mark point B at the intersection of the two lines you drew, and measure distance AB which will be useful later.
On the pocket, mark point A where the waist line and side meet. Draw a line parallel to the straight grain going through point A, then measure and mark distance AB along this line. Draw a line perpendicular to the straight grain going through point B.
Trace the pattern piece in size 44 (hip measurement) below this line, and in size 42 (waist measurement) at the upper edge of the piece. Using a curved ruler, draw a line between sizes 44 and 42 along the side seam.
Trace the upper edge of the pocket facing piece in size 42 (waist measurement), as well as the diagonal pocket opening. Overlay your graded pocket piece (#4) on the pocket facing and trace the side seam below the diagonal line.
Overlay your new pocket facing piece (#3) on the side front, aligning the top of the pocket facing with the line for size 42 (waist measurement) of the side front piece. Trace the upper edge of the piece following the pocket facing, and finish tracing the bottom of the leg in size 44 (hip measurement).
Trace the center front piece in size 42 (waist measurement) from the top of the piece down to the bottom of the fly, then in size 44 (hip measurement) from the bottom of the crotch curve to the bottom of the leg. Using a curved ruler, draw a line between sizes 44 and 42 along the crotch curve.