Opted to change store (5)
I believe the answer is:
depot
'store' is the definition.
(depot can mean a store or warehouse)
'opted to change' is the wordplay.
'to change' indicates anagramming the letters.
'opted' with letters rearranged gives 'DEPOT'.
(Other definitions for depot that I've seen before include "Regimental HQ" , "Bus station or warehouse" , "storeroom" , "Storehouse, repository" , "Storehouse as for supplies" .)