Gandhi believed that man can achieve reform through nonviolent means. How did Gandhi demonstrate this belief?

Gandhi demonstrated his belief in reform through nonviolence by a lifetime of nonviolent political protest that began when he faced racial discrimination in South Africa. He is especially known, however, for organizing nonviolent actions to oppose British rule in India. He believed that nonviolence was key to achieving Indian self-rule.
In 1915, he led a nonviolent protest against high taxes on land in India. In 1930, he led the Dandi Salt March, another nonviolent action, to protest the British salt tax. In 1942, Gandhi again used nonviolent tactics to advocate for Indian independence from British rule.
Gandhi lived his faith in nonviolence through training himself and others in the spiritual discipline of satyagraha, a term that means "the force of truth" or "truth as force." It is based on the idea of speaking and acting out of truth and love. Gandhi insisted that his followers spend time on his ashram being trained in satyagraha before they joined him in nonviolent resistance. He knew that people who lacked this spiritual discipline were far too likely—as is only natural—to respond violently to violence. He knew that responding violently, however, would play into his opponent's hands and divert attention from the message of he wished to convey.
Martin Luther King studied Gandhi's tactics and also had his followers trained in nonviolent resistance.
Gandhi did not simply speak or write about nonviolent protest; instead, he practiced it throughout his life and taught it to others. Although we live in societies that often believe that violence is the only solution to problems, Gandhi showed that another path could be highly effective.