If by "this Wednesday" you mean tomorrow, then as SM, I don't think there is much to be done. Noises Off is a farce with loads of physical comedy. It's the type of show where you must have significant rehearsal time on the set so that the comedy reads to the audience and is safe for the actors (falling down the stairs takes a while to work). In my opinion the best thing you can do to help is to do your best to make sure everyone stays safe. Sounds like you're going to be at a frantic pace over the next 24 hours and safety can easily be compromised and overlooked in the interest of throwing things together as quickly as possible.