HiOK try this, remove the caliper as if you were changing the pads, wind the piston back in slowly, check that the cable is routed correctly and the outer cable case is located in the in the guide on the caliper, after you have put the pads back in dont touch the caliper or the brake pedal, now do exactly the same to the other caliper, once you have put the pads back in and refitted the caliper get in your car and pump the brakes via the brake pedal no need to start the car, once you have pumped the brakes pedal until its hard, now pull the handbrake a couple of times this will now take any slack up on the handbrake.........if your handbrake is working properly
For future reference never pull the handbrake on until you have pumped the brake pedal to take up the slack in the caliper.
I don't understand why you are saying to remove the pads and calipers, there is nothing wrong with them they are working 100 % fine the problem is not to do with any of those but the cable for the handbrake.
I do not want to mess with the calipers as those pistons can be a nightmare to wind back in on the rear, they are all 7 months old basically brand new and fully operating.
I only want ot know how to sort out the handbrake , thanks