The ultimate biggest Truth of life is that you are not body and mind. There is no relation between you and them. There functioning is automatic and not related to you. Then what you are? You are Observer/Awareness/Consciousness.
If it is so why it is not clearly visible? Why we consider our self to be body and mind? From many life we are inside body and mind. We are so attached to it that we considers it to be us.
What is the path to separate our self from mind and body? Meditation is that path. During practice of meditation we gradually get away from mind and body. One more thing is required. We should continuously keep listening to the discourses of enlightened persons. These discourses help us in cleaning our mind.
See following video which explains from biological point of view, how we are not body and mind.