Re: change in plans - uh-oh
There are a number of things you can do. The easiest thing will be to change from 12' sheets to 8' sheets. The benefits are that they're lighter to handle and easier to shoehorn in tight spots, such as that staircase. The only down side to the shorter sheet is a slight bit more taping.
You could rent a lift to get the rock upstairs from the outside. Remove a window for access. This, of course, would be the easiest way to get the rock upstairs, though will be a little more expensive in the lift rental and possibly dealing with the window.
Hire some local teens to help carry the rock upstairs.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!