Release holding pins and rotate the excess fabric in a clockwise direction dropping the fabric down to form the flare.
Measure flare right at base of form. Adjust the fold until the measurement matches the measurement A-B from the front drape (Lift the fabric higher at the waist to make the flare smaller, lower it to make the flare larger).
Pin at waist.
Trim excess fabric at waist from princess line to side seam, clip seam.