Changing of editor, highly desirable (2,3,3)
I believe the answer is:
to die for
'highly desirable' is the definition.
(I've seen this before)
'changing of editor' is the wordplay.
'changing' indicates an anagram.
'of'+'editor'='ofeditor'
'ofeditor' is an anagram of 'TO DIE FOR'.
(Other definitions for to die for that I've seen before include "Highly desirable or alluring" , "Extremely desirable (colloq.)" , "hot" , "Superb" .)