The center/home screen is now the top screen and is always accessible by swiping down. There are now 4 screens, a top, bottom, left and right one. Don't think about the screen you were just on, only think about the screen you want to go to. If you want to go to the top screen, drag down; If you want to go to the left screen, drag right; If you want to go to the right screen, drag left; If you want to the bottom screen, drag up. Don't try to go back to a screen, always go forward to the screen you want.