I used a combination of wrenches to loosen the most difficult bolt, then used a flex drive to remove it. It was the most difficult part of the job. I spent as much time on that step as the rest of the job combined. If you're using the HeaterTreater parts, it is not necessary to cut the intake grill out. The door will install from the bottom where the blower motor is located. See if you can search my old posts and find several pictures I posted. I would repost them but they're not on my Mac.