Place the palm of one hand on the point of your horse’s sternum (between the two pectoral muscles) and then place your other hand on the horses withers. Apply gradual and gentle pressure to your horses sternum. Then gently mobilise the sternum backwards.
Rock backwards and hold for the prescribed time before releasing the pressure and repeat as recommended.
Ideally you will see a softening response to your horses face, with gentle blinking and potentially chewing. If your horse moves away or raises their head/neck you may be applying too much pressure.