Reform needed by shopkeepers (6)

I believe the answer is:

change

I'm a little stuck... Click here to teach me more about this clue!

'reform' is the definition.
(I've seen this before)

I don't understand how the rest of the clue works.

(Other definitions for change that I've seen before include "Cash" , "Alter, modify" , "Money returned as balance after purchase" , "Coppers, perhaps" , "Alteration" .)

I've seen this clue in The Globe and Mail.

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