My big safe is about 900 lbs empty. I've got a walkout basement, with a reasonably steep slope on the side of the house. Two guys used a dolly to deliver it and install it. The right knowledge and equipment allows folks to do that sort of thing without a large group of people.
I don't have a walk in...they had to use this moterized sled/tank thing and a pallet jack because of the size of the safe and the size of my bulkhead into the cellar. It almost wasn't coming into the house...but somehow those guys got it in... They knew what they were doing...I was impressed...