I heard for the change up to grip it deep in the hand. Is that the same for the circle change up? If so, how deep in the hand should I hold it (with pics or something please)?
Holding the ball deep in the hand is not necessary with the circle change. The circle grip works by taking a strong finger (the index finger) off the ball and replacing it with a weaker finger (the ring finger). Pronating further reduces velocity.
Your control will likely be better if you keep the ball in the fingers and if you cut the ball in half with thumb and middle finger.
Ok, thank you Roger!