Fold to right sides out and press. With right sides together, at the side seams, sew the front to the back and the front facings to the back facings. Hem the top. Only the back neckline need be faced. All other edges are just serged turned under and topstitched.
Serge finish all edges except neckline back.
With wrong sides together, stitch the back neck facing to the back. Press the seam open, understitch and trim. Press the facing to the wrong side. With right sides together, match the front to the side front and stitch. With right sides together, stitch the fronts to the backs at the shoulder seams.