All these stretches must be done in a slow and controlled movement, no bounce and keep the spine in neutral for all these stretches, always do both sides.
Start with an upright position, drop the arm on the side you want to stretch, then place the opposite hand over the top of your head and just rest it there. Now apply a downward pull on the arm toward the floor, until you feel the stretch and hold for 10-15 seconds.
This is similar to the above but start with the head rotated to the side before applying the downward pull. 7-10 sec
Start with the head in neutral, pull your chin in, then lower your head towards your chest. Place your hands on the top of your head and let them rest. You should feel a stretch from the base of the skull and down the centre of the upper back.