I agree with Ginger. Cut the lining to match the apron, prepare the ties and pin or baste in place. Sew all the way around the apron leaving an opening. I'm guessing a half inch seam. Be sure to catch the ties in the stitching. Clip the fabric on the curves every half inch or so, but be careful not to nick your machine stitching. then turn. hand or machine stitch the opening.