Step 1: Background
Step 2: Research
Step 3: Make a Template
Compare how it fits to the sweatshirt by placing above the sweatshirt on the hanger.
Make a template of the collar so it can be compared to the extra hood material and the hoodie. There should be plenty of material. I compared half the collar template to half the hood.
On the overlapping jacket and hoodie picture, the edges line up well so I plan to just fold the sweatshirt back and sew material on the inside of the sweatshirt.
The triangles on the outside of the template will need to be cut out of the hood, then sewn on the inside where the zipper was.