In case you did not know the iPhone's battery is not removable which was one of the drawbacks of the iPhone. So in case the battery dies you have to send the phone to Apple for replacement. However you can get a spare battery and replace the battery by following this simple tutorial.
Nate and I got together to film this this tutorial, which shows how to replace your iPhone battery. Heck, even if you have decided that you will never open up your iPhone on your own, we think it’s still pretty cool to see the process - so just hit play, okay?
Via - Gearlive