The best way to do this is to try it, working with friends or in small groups at first, and starting with roleplays or less intimidating activities like leafletting. As confidence in our own resourcefulness grows, we become more able to support each other in maintaining our nonviolent actions. The myth that emotions are destructive and unreliable prevents us from trusting our own experience and forces us to rely on rigid formulas and people we perceive as authorities for guidance. Most of us have been taught that expressing anger especially provokes disapproval, invalidation and physical attack, or else will hurt others and make us suffer guilt. This conditioning serves to make us both repress our own anger and also respond repressively to each other's anger.
Anger is a sign of life.
It arises with recognition that injustice exists and contains the hope that things can be different. For now it believes and yet it doesn't quite dare to believe that it can claim its rights at last. To make room for a healthy expression of and response to this anger, it helps to create a general attitude of respect and support. When people sense this happening, they should pause and consider their feelings and objectives. It is the willingness to undergo suffering rather than inflict it.