Repair or restore (6)
I believe the answer is:
revamp
I believe this clue is a double definition.
'repair' is the first definition.
(revamping is a kind of repairing)
'restore' is the second definition.
(revamping is a kind of restoring)
(Other definitions for revamp that I've seen before include "Give makeover to" , "Give new appearance to" , "New and improved version" , "Make new, improve or up-date" , "overhaul" .)