Just by looking at the picture, you will already know how to do it yourself.
First, totally remove the sleeves. Cut and form a V-shape for the neckline. Continue snipping at the upper part of the back but make sure to remain 2 lengthy strips for the halter’s strap.
This D-I-Y project is simple though it needs sewing, just the basic sewing skill. If you know how to do the back stitch then there you have it. You only have to sew the back part where you add the garter.
Now, it’s done!