Step 1:
This is the front of the paper, turn the paper.

Step 6:
Pull the corners indicated by the 2 arrows upwards again.

Step 5:
Valley-fold over 2 lines and mountain-fold over the other 2 lines.

Step 2:
Valley-fold over these 4 lines.

Step 4:
Prefold over these 4 lines.

Step 3:
Prefold over these 2 lines.

Step 10:
Mountain-fold over this line.

Step 8:
Valley-fold over these 3 lines. Then push the edges downwards again, see arrows.

Step 9:
Valley-fold the corner downwards.

Step 7:
Pull the edges indicated by the 2 arrows upwards again.

Step 16:
Repeat step 15 on the other side, see arrow.

Step 15:
Valley-fold over the 2 inner lines and mountain-fold over the 2 outer lines. Valley-fold over the 3 yellow lines while you do this.

Step 12:
Turn the model.

Step 11:
Repeat steps 7 to 10 on the corner indicated by the arrow.

Step 14:
Prefold over these 4 lines.

Step 13:
Valley-fold over these 4 lines.

Step 21:
Insert the little flap of step 19 in the opening indicated by the arrow on the left.

Step 19:
Push/pull this flap outwards.

Step 20:
Push/pull this green edge outwards a little.

Step 18:
Push the 2 corners below in the corners indicated by the 2 upper arrows.

Step 17:
Valley-fold the model in half.