Make the first cut under the axillary area dividing shirt into two parts.

Sew hem on the cut area.
Fold the shirt of 1 cm at the waist.
First inside seam, second outside seam.

Insert elastic at waist to create the curl.

Cut and fold a sleeve,join the sleeve to the shirt with a second elastic.

Remove the original buttons and replace them on the front and on the back of the shirt.

Apply a belt the same color of buttons. I made the belt taking a red ribbon, a red button and a piece of fabric shirt.