on top of the tallest building there is a diskette that summons a box of weapons, take a barrel of balloons (which is under the flags there will be a wall and in the corner there will be a barrel of balloons) and fly to the top, when getting there will have a container (with a door and window) between it and there will be a table on top of the table will have the diskette.
Then enter the cinema, go up the stairs and upstairs in a room there will be a computer (old) just use it.
(You can use the balloon barrel to get out of Swindow too.)