Using pencil, draw two shapes from the bottom side of the carton for, 1. the eyes and beak and 2. the ear/feather tufts that go above and behind the eyes and beak. Then cut them out with scissors.
On one end of the top of the carton, draw a shape sort of like this; then cut the shape out (the head will slot in that section.) When your head is ready, you may need to add a couple of vertical cuts to firmly slot it into the body (see vertical cuts under the beak in the finished, yellow owl picture at the top of the page.)
Next, on the other end of the lid, draw some feet and cut out the section under the feet. Draw in some "U" shaped feathers and use a craft knife to cut around them (probably not a job for young children.) Then bend in the bottom of each side of the lid on a diagonal. The dotted line above indicates where you should bend the carton.
Cut feather shapes around the eyes of your owl if you wish. I cut slits and points and curved them under to give a feather appearance around the eyes. Do the same or create your own eye design. Then cut and gently shape the beak.
Glue the ear piece behind the eyes. A piece of tape will help hold it in position while it dries.
When it's dry slot it in place on top of the owl body.