撥 亂 反 正 bō luàn fǎn zhèng : bring order out of chaos; set to rights things which have been thrown into disorder

不 虛 此 行 bù xū cǐ xíng : the trip has not been made in vain; the trip has been well worthwhile; it's been a worthwhile trip

代 之 以 dài zhī yǐ : (has been) replaced with; (its) place has been taken by