17. Bring the top layer diagonally down to the left.
18. Flip the paper over to the other side, from left to right.
19. Bring the top layer diagonally down to the right.
20. Fold the flap diagonally over and down to the left as shown.
21. Bring the other flap down from behind to match.
22. Fold the top point diagonally over to the left, using the creases underneath as a guide.
23. Open the model up a bit and place it in this position.
24. Bring the two sides inwards so that you have this.