I have kept up with this thread from the day it was posted and put all the advice applicable to me in action yesterday when I bought and setup a 550 lbs safe. My father and uncle were drafted into service to help. We used a pickup truck to transport it from the store but could not slide it out by hand. It was 4 inches from where the truck bed ends and the cab begins, so we could not get behind it. We solved this by attaching a rope to the safe (still in card board shipping box) and dragging it out a few feet with a heavy duty ATV. Once that was done, it was a breeze to slide it out by hand and guide it safely to the ground.
My $ 25.00 dolly was not up to the task of moving it, so I rented an appliance dolly. I had never heard of these special dollies before reading this thread. I also took another posters advice and did a dry run with just the appliance dolly. I measured everything before hand, but the dry run showed that an interior door had to be taken off to ensure a damage-less entry. We took our time and everything turned out fine. Thanks for all the tips.