1
general::
Punish severely, as in If I find the guy who slashed my tire I'll skin him alive. This hyperbolic expression transfers the barbaric practice of flaying a live prisoner to other forms of punishment. [Colloquial; mid-1800s]
American Heritage Idioms
2
general::
Phrase(s): skin someone alive
Fig. to be very angry with someone; to scold someone severely. (Fig. on being angry enough to do this kind of bodily harm to someone.) • I was so mad at Jane that I could have skinned her alive. • If I don’t get home on time, my parents will skin me alive.
McGrawhill's American Idioms And Phrasal Verbs