Step 1
Get the pattern (front and back are the same, only the neckline changes) and raise the sleeve/shoulder tip by 3cm, then extend it and alter the sleeve opening as shown in the photo.
Mark a rectangular piece at the underbust 17×2,5cm for the elastic.
Increase the length to 71cm.
Draft the hoodie starting from a rectangular shape 33x39cm, the bottom side should be slightly curved as the necklines are.