Secure changes for free (6)
I believe the answer is:
rescue
'free' is the definition.
(I've seen this in another clue)
'secure changes' is the wordplay.
'changes' indicates an anagram.
'secure' anagrammed gives 'RESCUE'.
'for' is the link.
(Other definitions for rescue that I've seen before include "Deliver from harm" , "saving" , "Save from danger or distress" , "Deliver from danger" , "Save from peril" .)