Alters, makes right (6)
I believe the answer is:
amends
I believe this clue is a double definition.
'alters' is the first definition.
(amending is a kind of altering)
'makes right' is the second definition.
(amending is a kind of making right)
(Other definitions for amends that I've seen before include "They're made to compensate" , "Make these to atone for wrong done" , "Makes changes, to a text say" , "Improves - damages" , "Atonement" .)