Modify, correct (5)
I believe the answer is:
amend
I believe this is a double definition.
'modify' is the first definition.
(I know that amend is a more specific form of modify)
'correct' is the second definition.
(amending is a kind of correcting)
(Other definitions for amend that I've seen before include "Change for the better" , "Corrct error, make a minor aleration" , "Revise" , "Ameliorate" , "Change, alter" .)