Exhalation is performed inversely to inhalation. That is, first release the upper section of the lungs, then the middle and finally - the bottom, contracting your abdomen.
呼气的步骤正是吸气的相反。那就是，先呼出肺顶部的气，然後肺的中部，再到最後，肺的底部，收缩肚子。