How do you get into the alley way on animal crossing

Do you mean the one in the city? If you do, I can answer that =) At 8:00 pm exactly, go to the city. When you get off the bus, take a sharp right turn - don't go up the steps. The cone should be moved to the side and allow you access. It is Resetti's surveillance centre. He will give you a silver shovel as a reward. Thanks! <3 Jas