Have a partner come at you with a fist toward your face. Hold your breath and tense up your body. As the contact comes exhale and relax your entire body to the ground. Repeat this drill from all directions forward backside and sides and from different angles. Change roles and repeat and then add adding your limbs to the collapse exhale so you continue to move instead of crumble to the ground (the more you spread your awareness the less frozen you will feel under pressure)
Add to the drill less and less tension and more continuous breath so you end up breathing normally and devoid of excess tension knowing the correct distance for you to move in and where to avoid getting harmful contact and knowing what to do if you missed one or two.
Add another partner and repeat 🙂