That is The Times boss purged (7)
I believe the answer is:
scoured
'purged' is the definition.
The answer and definition can be both related to change as well as being past participle verbs.
Perhaps there's a link between them I don't understand?
'that is the times boss' is the wordplay.
'that is' becomes 'sc' (abbreviation for Latin scilicet meaning 'namely').
'the times' becomes 'our' (I am not sure about this - if you are sure you should believe this answer much more).
'boss' becomes 'ed' (short for editor - newspaper boss).
'sc'+'our'+'ed'='SCOURED'
Can you help me to learn more?
(Other definitions for scoured that I've seen before include "Scrubbed; searched" , "Washed" , "combed" .)