rear brakes won't bleed

Good chance that the safety switch in the distribution block has been tripped allowing front brakes but blocking the rears. Plunger must be re-centered to bleed.
What is the process to re center the plunger? I read that you open the front bleeder and push the brake pedal until you hear the click in distribution block so i am assuming that means the bleeder on one of the front brakes correct?