A student of Gandhi's principles, Martin Luther King Jr., once said that darkness cannot drive out darkness, only light can do that. And hate cannot drive out hate, only love can do that.
To me, this is the essence of ahimsa and a way to identify the potency of the concept of inspiring change through non-violence.
We can also see in King's words a practical idea, relatable to any large scale change. For instance, if a nation's peoples wish to overthrow a despotic regime and replace it with a democratic system, the best way to make the change is through democratic means. Clearly this is not easy, but if the overthrow is completely militant, absolutist, or party-driven, then when one tyranny falls it will simply be replaced by another.
The values we wish to see implemented in the course of change have to, somehow, be given a place in the process and mechanism of the change.