Our stair carpet is a disgrace, worn through in places, stained and scratched to blazes by now departed cats (not Maurice, he was a gentleman and would never have dreamed of doing such a thing)
We can't really afford to replace it, plus although Oliver Sprout is generally not a "scratcher" in a vandalisitc sort of way, he does enjoy a quick dig in of the claws when stretching.
An idea has been floated of removing the carpet and painting the stairs, perhaps just as a temporary measure
and have even found the right colour.
BUT it gives the drying time as 72 hours 
Previous exerience of varnishing a landing makes me think that the way to go is to paint one side first, giving access by walking up the other side (keep left/right signs put in position) but how on earth can I keep the cats off it???