We can't reply to posts properly there, so I'll make a new post. Lob the duvet over the banisters on the landing. Turn the cover inside-out and put your hands in the bottom two corners and hold onto them. Grab two corners of the duvet then hang it all over the stairs and give it a good jiggle. Because you're holding the two corners and it is inside out the cover should roll down and almost be on properly. Spin the duvet around so now it is hanging the other way. Grab the two top corners (where the opening is) and pull them to their corresponding corners on the duvet. Hold the lot together with a corner in each hand (just the two corners where the opening is) and give it a jiggle again. It should all be inside properly now. Tomorrow, how to hoover the stairs.