脫胎換骨　

◎ 脫胎換骨 tuōtāi-huàngǔ

[be reborn;change completely and thoroughly;create new things out of the old;turn over a new leaf] 道教徒認為人在苦修得道之后,就能脫下胎,換上骨?，F(xiàn)在常用來比喻痛改前非,重新做人