Sue changes employment (3)
I believe the answer is:
use
'employment' is the definition.
(how something is used)
'sue changes' is the wordplay.
'changes' is an anagram indicator.
'sue' is an anagram of 'USE'.
(Other definitions for use that I've seen before include "Avail oneself of" , "Apply, employ" , "Employment; utilise" , "consume; exploit" , "exercise" .)