Disconnect the handbrake cable from the quadrants on the calipers, and remove the brake discs, then manually operate each caliper until the disc just slides between the pads with the quadrant fully back on it's stop. Once that's done refit the discs, and then refit the cable, ensuring when you do that the quadrants remain on their stops. (Fully off.) If that's not the case adjust the cable until with the handbrake off the quadrants on the calipers are fully off.
but if I operate the handbrake lever long enough it will adjust it self?