The iPhone comes standard with the iTunes application, which lets you play MP3 songs on the device. You can remove any application on the iPhone, including the iTunes application. After you delete the application, you can download a new app from the iPhone app store or leave all MP3 playing programs off the phone to conserve storage space.
Press the "Home" key on the iPhone. The "Home" key is the large circle at the bottom of the phone. The button returns you to the main home screen of the iPhone.
Press and hold the iTunes application button on the home screen. When you hold the iPhone app buttons, they start to wiggle. This tells you that the buttons are in "Edit" mode.
Press the "X" icon at the top-right corner on the iTunes app button. Press "OK" to confirm that you want to remove the app from the phone.
Press the "Home" key again to return to the home screen and exit out of "Edit" mode.