idiom · to shed one's mortal body and exchange one's bones; to be reborn as a Daoist immortal

传说他得道成仙，已经脱胎换骨。

idiom · to create new artistic or literary works by transforming old material into something new

这部戏剧在传统故事的基础上脱胎换骨，赋予了现代意义。

idiom · to undergo a fundamental change in character or outlook; to turn over a new leaf

经过军营生活的洗礼，他整个人都脱胎换骨了。