how can you be an instrument of social change in this contemporary world?

For me I think that we each can do our part if we so desire change by volunteering. You won't get paid for it, but you will be making a difference in the life of others or those who are working for some change. For instance, people who have no homes, are having houses built for them by volunteers working with Habitat for Humality, and the list goes on, so yes, a person can a change if they volunteer.