Always use simple thinking.
A step with some 2x12s becomes a gradual ramp you can roll the dolley on.
For the dolley you want the heavy duty type that has the little wheels that hold the safe up when you tilt the dolley back. Basically the dolley supports all the weight and you just push and manuever.
Plywood and other wood is your friend. It is easy to mess up all types of flooring with a safe or a dolley and what not.
If you decide you can't do it call the pro movers in the phone book and find some who have done safes before. The nice thing is these guys should be insured for any damage they do to the flooring or walls.
I tend to avoid getting a bunch of friends to move my big stuff around because I don't want to deal with someone accidently getting hurt trying to help me move stuff.
With a super dolley and some stout wood I have moved all sorts of stuff myself.
One thing to consider on a step if you can't do a ramp is you just need to get the safe to that height. If you rock the safe back you can put a block of wood under the end that is in the air. Then you rock it onto that shim and get something under the other side. I recently loaded a huge stump onto a trailer doing this method with some concrete bricks. 2 or 3 guys may have been able to lift this thing, but a prybar and some blocks let me get the stump in the air to where I just made a 2x12 ramp and loaded it onto the trailer.
If you are forcing something you are working too hard and could hurt yourself or the safe or the house.
Think ramps, wheels, rolling pipe, pry bars, and similar things for being able to move stuff you should most likely not move yourself.
I generally do have someone around to watch the corners of walls and hall ways and to basically just spot me. They really help with placing the shims and stuff but they are not in much danger of getting hurt.
I am thinking about buying a huge safe and I will pay to get it moved. For safes like what sam's club sells I can do it but I have to think about it a while.