Detachment is not indifference. it is the prerequisite for effective involvement. Often what we think is best for others is distorted by our attachments to our opinions. We want others to be happy in the way we think they should be happy. It is only when we want nothing for ourselves that we are able to see clearly into others needs and understand how to serve them.
The chief helps in this liberation are Abhyasa and Vairagya. Vairagya is non - attachment to life, because it is the will to enjoy that brings all this bondage in its train; and Abhyasa is constant practice of any one of the Yogas.
One must know oneself as one is, not as one wishes to be, which is merely an ideal and therefore fictitious, unreal; it is only that which is that can be transformed, not that which you wish to be.