I have moved safes a number of times. I would highly recommend hiring a pro. Especially if you are in a profession that an injury might keep you out of your regular job and result in no pay for you for a while.
Not criticizing at all, but Tarkio has it. I was a mover on the side for a decade (HS/college), and cliche though it may be, if you have to ask...
I've been hired to clean up some disastrous failed attempts at moving heavy pieces, including see porches, sub-floors and stairs collapse. Memorable items offhand I recall that were *beasts*: a 350 Chevy V8, to the 5th floor, with the last two floors not large enough to have more than two men on it... A 12 X 4 X 3 fish tank, with about 40 gallons of water and the rocks still in it... A few large safes weighing perhaps 1200 lbs. It ain't that big of a deal if your brother loses his grip on a fridge that comes down a steep set of stairs at the guy below (though it certainly can be good for an ER visit). Try that with a half ton of steel safe and people can DIE. Not to mention do some *very* expensive damage to the item, as well as the home.
We always used leverage, mechanical assists, straps and the most important thing: your head. Pay some outfit to do it. Make sure they're insured and know WTF they're doing.
