He's to be changed, not these (5)
I believe the answer is:
those
'not these' is the definition.
(I've seen this before)
'he's to be changed' is the wordplay.
'be changed' indicates anagramming the letters.
'hes'+'to'='hesto'
'hesto' is an anagram of 'THOSE'.
(Other definitions for those that I've seen before include "Plural form of that" , "Ethos (anag.)" , "the more far out?" , "Nostalgic utterance" , "The (things) there" .)