picture is enlarged
Fold and unfold (valley fold)
Also, mountain fold
Open roundly
Squash it a little with fingers
The other three places are folded in the same way as processes 23 - 30, too.
Finished !!
It's needed 40 parts.
memo
The basic number of parts are 40, but when you get them together into the whole, observe the state of the work and please add or reduce parts suitably.