How to update to iOS 7: Required files: select the required download file from the links shared below - remember this is not an official posting so files might become unavailable.
iPhone 4 (GSM), iPhone 4 (GSM Rev. A) iPhone 4 (CDMA) iPhone 4S iPhone 5 (Model A1428), iPhone 5 (Model A1429) iPad 2 (Wi-Fi), iPad 2 (Rev. A), iPad 2 (Wi-Fi + GSM), iPad 2 (Wi-Fi + CDMA) iPad 3 (Wi-Fi), iPad 3 (Wi-Fi + GSM), iPad 3 (Wi-Fi + CDMA) iPad 4 (Wi-Fi), iPad 4 (Wi-Fi + GSM), iPad 4 (Wi-Fi + CDMA)P iPad mini (Wi-Fi), iPad mini (Wi-Fi + GSM), iPad mini (Wi-Fi + CDMA) iPod touch (5th Generation) iTunes 11.1 Beta
Open the disk image (.dmg file) and find the iPhone Software Update file (.ipsw) for your Apple device. Drag the ipsw to the desktop, or any other folder of your choosing. For those on Windows, use a tool like 7-Zip to do this. Next open iTunes and connect your iPhone, iPad, or iPod touch to your computer. In case your device doesn’t get automatically selected in iTunes, select it and go to the Summary tab. In OS X, hold down the option key; use the shift key in Windows and click the Restore button. Locate the .ipsw file that you downloaded and select it. Wait for the update to be finished. If you want, restore your Apple device from backup and sync with iTunes.
Ta da! With the steps above, you can update your device to iOS 7 in no time!