Register right, make changes again (8)
I believe the answer is:
readjust
'make changes again' is the definition.
(I've seen this before)
'register right' is the wordplay.
'register' becomes 'read' (synonyms).
'right' becomes 'just' (associated in meaning).
'read'+'just'='READJUST'
(Other definitions for readjust that I've seen before include "Adapt again" , "Once again tune" , "Change again" , "Set or arrange again" , "settle again" .)