On both front and back draw a parallel to the hem 15 cm above.

On front only, draw a slash line from the dart top to the neckline.

Make a copy of the front, shortened, closing the dart and opening 4 to 6cm at the neckline.

Reshape both the neckline and the side seam.

Trace also a copy of the back (we mirrored both front and back) and draw a ruffle 15x150cm for the hem.

Here is the sewing process and here the way of finishing neckline and shoulder straps.