waterpau

Hi all, Have a binding brake on the rear left wheel. As a first step we've tried replacing the caliper, but due to a suspect incorrect part, we've put the old caliper back on. However the tension in the cable is making it impossible to re-hook. We released the EPB and disconnected the battery beforehand, but wonder if there's a step we've missed to reconnecting the cable onto the back of the caliper? Any thoughts appreciated waterpau