WEAR A GOOD FACE MASK when you are doing all this cleaning, to protect yourself from the dust and crud you'll be inhaling otherwise. Realize that you can make the coop better, but it can't be truly made sanitary. Do your best anyway, get the big hunks out. Keep it empty for at least two to three weeks, and spray with insecticide (Sevin or Poultry Dust) . Talk to the owner of the chickens who just left; ask about any illnesses she may have to report. I'd plan on getting a few Marek's vaccinated chicks at first, and giving it this year to see how they all do. If all is well, you'll have a great start! Mary