My top floor bathroom's exhaust fan is noisy. The plan is to replace it with a new one. My challenge is my attic. First off, I have about 40 inches of bat insulation up there. I know that is more than needed. Is there a safe way to move in the attic so that I stay on the structure and not go through the ceiling? What should I wear to protect me from the fibreglass? Is it possible to remove the old one and put the new one up all without going into the attic?