According to Osho, no—willpower can move the gross body (fasting, walking, sitting), but it cannot separate the subtle from the physical. Real separation is not a feat of force; it is disidentification born of witnessing and tathata. Walk, eat, live—while knowing you are not the doer. Through choiceless awareness and acceptance, the knot of identification loosens; nothing is torn apart, only seen rightly.
You can’t force your spirit away from your body; just watch calmly and accept, and you’ll realize you aren’t the body.