Make more modern (4)
'make more modern' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for update that I've seen before include "Correct - modernise" , "account of the latest developments" , "Something fresh" , "Bring to present status, say accounts" , "Latest information" .)
(Other definitions for redo that I've seen before include "Carry out again" , "Have second thoughts" , "Perform (action) again" , "Fashion again" , "Create again" .)