HT4623: Update your iPhone, iPad, or iPod touchLearn about Update your iPhone, iPad, or iPod touch
Currently Being ModeratedOct 13, 2012 9:29 PM (in response to redval)
Plug your iPhone into your computer and open iTunes. Select your device on the left sidebar. Now you'll see your iPhone summary page which has a "Check for updates" button.
If there is an update it will prompt you to download or download and install.