How to Change the Bottom Icons on an iPhone
In addition to providing traditional cell phone functionality, the Apple iPhone allows users to access the Internet, play and manage songs through an iPod interface, and download and install thousands of third-party applications that extend the device's capabilities. By default, the iPhone displays icons for four applications across the bottom bar of the home screen: Phone, Mail, Safari and iPod. Changing the icons that display in this bar is quick and easy once you learn how to open the editing mode.
Click any icon on the iPhone home screen and hold your click for at least two seconds. The icons on the screen will begin to shake, indicating that editing mode is active.
Drag icons away from the bottom menu bar to remove them. Similarly, drag icons from other areas of the home screen into the bottom bar to add them.
Click the "Home" button of your iPhone to stop the icons from shaking and close editing mode. The changes to the bottom bar have been confirmed.