When you get Price's Crib, walk into the room that lets you save, get cash, change clothes, and get weapons. Go to the north wall. There will be three doors. Open the door on the left. The one on the right should be the door you entered the room with, and the one in the middle cannot be opened. When you open the door, walk out just a little and turn left. Jump over the balcony and onto the roof. Make your way up the roof until you get to the peak. Turn left and you should see a chimney. Run over to it and press X to climb up. When you are on top you will see a soccer ball. Give it a good kick to get it out.