Remove the brake calipers and the pads. To push the caliper pistons back you need a special tool as they must be turned whilst applying pressure to push them back.
Replace the pads as normal, refit the calipers and wheels. Pump the brake pedal to push the pistons back out. Now you can turn on the ignition and operate the handbrake. There is no need to adjust the handbrake it does that all itself.
You do NOT need to operate the emergency handbrake release that is found in the boot of the car.How do you change the rear brake pads on a renault scenic with electronic handbrake?There's a covered compartment in the boot floor which contains a wire with a plastic handle which you pull to release the parking brake.