Take a small balloon, something the size if a baseball and fill it with ammonia. Just the kind you buy at the grocery store. Fill the balloon up and tie it off like a water balloon. Buy a cheap pack of hot dogs and drain the juice out of he package. Rub the juice all over the balloon and place it under your porch. The skunk will think the balloon is edible and pop the balloon. The smell will run the skunk out. I have a friend that owns a nuisance animal removal company and he has used this with great results. Just make sure your skunk is not under there when you go to place the balloon under there. Good Luck!