Like Max said, DO NOT USE AN ALLEN!!!! It is a t-60 torx head to remove the bracket. The use of an allen will ruin the head of the bolt, and you will not be able to get them out. Use a little heat to loosen the factory threadlocker on the threads and it will come out much easier.. If you're replacing rotors, the bracket has to come off. As long as you are careful pushing the piston back, and close the bleeder before removing the c-clamp so air can't get in, you shouldn't have to bleed the system.