Coppers; convert (6)
I believe the answer is:
change
This clue is a double definition.
'coppers' is the first definition.
(I've seen this before)
'convert' is the second definition.
(synonyms)
(Other definitions for change that I've seen before include "reform" , "Loose money in pocket" , "Novelty" , "Make or become different" , "we vary our routine for one" .)