Fix brace attached to exterior of residence (6)
I believe the answer is:
repair
'fix' is the definition.
('repair' can be a synonym of 'fix')
'brace attached to exterior of residence' is the wordplay.
'brace' becomes 'pair' ('pair' can be a synonym of 'brace'**).
'attached to' is a charade indicator (letters next to each other).
'exterior of' means to remove the middle letters.
'residence' with its middle taken out is 're'.
'pair' after 're' is 'REPAIR'.
(Other definitions for repair that I've seen before include "darn?" , "Mend, put right" , "Restore to working order" , "retire" , "Proceed - restore" .)