脫胎換骨

To take off or remove clothing or accessories; to shed skin or leaves; to escape or get away from; to leak or be missing; to sell off.

fetus; unborn child; womb; origin; source; padding; classifier for litters; tire

To exchange or swap; to change or alter; to substitute or replace; to convert currency.

Bone; skeleton; the hard framework of an animal's body; a supporting structure; character; spirit; backbone.