Heres what I would do:
Take a couple 2x4s and screw them down to two furniture dollies such that the ends stick out beyond the length of the tank.
Strap the 2x4s with the dollies to the tank with tie downs.
Roll the tank to the door. Now, using glass clamps on the tank and hands on the wood sticking out, lift and slide till the dollie sits on the top step and the tank is supported at the back by the wood touching the ground. Then lift and slide it from the back, rolling the front dollie into the house. If you need to rest, rest it on the lip of the door and the 2x4s. Slide it all the way in.....position it...job done.
heres my tank coming in the door, kind of the same idea: (middle of the page)
http://archive.reefcentral.com/forum...&pagenumber=14
Paul.