How to Update to iOS 4.2

As expected, the latest firmware update of Apple's mobile operating system, iOS 4.2.1 for iPhone, iPod touch and iPad, went live about 5 hours ago and is now available through iTunes. You can also get the update via direct download links which are provided towards the end of this post.
iOS 4.2
How to update to iOS 4.2
  1. If you don't have it yet, download and install iTunes 10.1 for Windows and Mac OS X.
  2. Connect your iPhone or iPod Touch to your computer via USB and start the iTunes.
  3. On the box as shown above, click on “Download and Update” button to get the new firmware update.
iOS 4.2.1 Direct Links: