Remove misbehaving sergeant (8)
I believe the answer is:
estrange
'remove' is the definition.
(estranging is a kind of removing)
'misbehaving sergeant' is the wordplay.
'misbehaving' is an anagram indicator.
'sergeant' is an anagram of 'ESTRANGE'.
(Other definitions for estrange that I've seen before include "Lose friendship" , "Anger set (anag.)" , "Get on the wrong side of" , "drive apart" , "turn away?" .)