The Monkey is associated with the Dui trigram. Dui is a marsh or lake, the single Yin line above the double Yang lines representing water lying on the earth. Dui represents the mouth in the body. In the martial arts, it is the Embracing palm and the right side of the waist.
Sun Lutang starts the Monkey Palm Change from the Pushing the Millstone Palm posture, then assumes Holding the Fruit Palm after the first Single Palm Change. As I have noted in the other animals, I prefer to start in the Mother Palm posture.
Toe-in as if doing the Single Palm Change, but do not change the position of the hands.
Toe-out and move the arms into the Green Dragon Returns Its Head posture of the other palm changes. Notice the compact nature imposed by the original Holding the Fruit posture.
As an alternative, before performing Green Dragon Returns its Head, you could do a Snake Lies in the Grass, then complete a Single Palm Change.
As you complete a Single Palm Change, turn your palms to face up with the pinkies touching each other. Now walk the circle in the opposite direction.
The Dui trigram is the opposite of Sun and the Phoenix Palm Change. Where the Phoenix has a yin line below, the Monkey has a yin line on top. This implies the top soft, while the bottom is stable. Thus, the compact nature of this change.
I prefer adding the White Snake in the Grass movement to the Monkey Palm Change. It seems like an obvious choice after walking the circle with the two hands pressed together and the palms facing upward. Both changes are acceptable. In either one, you are completing a Single Palm Change before walking the opposite direction.