settle down -
become quiet or calm, especially after a state of agitation; "After the fight both men need to cool off."; "It took a while after the baby was born for things to settle down again."
change state,
turn undergo a transformation or a change of position or action; "We turned from Socialism to Capitalism"; "The people turned against the President when he stole the election"
settle down -
become settled or established and stable in one's residence or life style; "He finally settled down"