September 19, 2012, 5:19 PM — Here's how you can upgrade your iPhone to iOS 6 via Wi-Fi. No need to connect your iPhone to iTunes.
1. Open the Settings app.
2. Tap on General.
3. Tap on Software Update.
4. Install your iOS 6 upgrade on your iPhone.
For more, see the original article at the link below.
iOS 6 Has Been Released, Download Now! | OS X Daily