(５１)
Fold the left head/tail to the center like this picture.
Then unfold the head/tail.
(５２)
Unfold the head/tail like this picture.
Then raise the head/tail as it is.
(５３)
Raise the head/tail as it is like this picture.
(５４)
Then fold the other head/tail to the center.
(５５)
After folding the head/tail, unfold it.
(５６)
Unfold the head/tail like this picture.
Then raise the head/tail as it is.
(５７)
Raise the head/tail as it is like this picture.
(５８)
Then prepare to put the top part on the bottom part.
(５９)
Make mountain-folds on the dotted lines.
(On the other side, make mountain-folds on the dotted lines as well.)
(６０)
After making mountain-folds, it looks like this picture.
(６１)
Then insert the top part in the bottom part.
(６２)
This picture is halfway through.
(６３)
Insert the top part in the bottom part like this picture.
(６４)
This picture is taken from the other side.
