During the WWDC keynote, Apple demoed several of the new features in iOS 6, including Facebook integration, the new Maps app, turn-by-turn directions, a "Do Not Disturb" feature for when you don't want to answer your phone, and several enhancements that make Siri "smarter." In total, iOS 6 brings more than 200 new features over iOS 5 and, with today's announcement, tons of app developers are flocking to Apple's iOS Dev Center to download the beta.
Before you can even think about installing the iOS 6 beta you'll need to have an iOS developer account, or know someone who has an iOS developer account. The iOS developer program costs $99 per year for individuals and $299 for companies wishing to develop iOS apps.
Next, you'll need to make sure the UDID of the iOS device or devices you wish to test on are registered with the iOS developer program, thus making your device eligible to install beta iOS software from Apple on.
Before I go any further, I want to make it clear that this software is intended for developers who are working on creating or updating apps. If you load iOS 6 beta you'll have horrible battery life, some features flat-out won't work, and the overall experience will be trying at times. And there is no easy way to revert your device to running iOS 5 once you have loaded iOS 6 on it. Beta testing isn't for everyone, no matter how cool it may seem to be on the bleeding edge of software. Bottom line: don't load iOS 6 if you aren't prepared for hours of frustration.
Let's get started with loading iOS 6.
You'll need to be running iTunes 10.6.3, which was released shortly after the keynote speech. You'll also need the iOS 6 beta file or files for your respective device or devices. All of the files are available in the developer center for registered developers.
Connect and back up your device using iTunes. Restoring from an iCloud backup is possible with iOS 6, but I wouldn't recommend it. This is a beta; things go wrong. Make sure you encrypt the local backup, as doing so saves you from having to enter account passwords and the like after a restore.
Once the backup is complete, hold down Option on your keyboard and click on Restore.
Select the matching IPSW file for the device you are loading iOS 6 on.
iTunes will then extract the software and install it on your iOS device. You'll see your device reboot a few times and the screen will flash some different graphics during the install process. The entire installation should take about 10 minutes. But don't be alarmed if it does take longer, just be patient.
After the installation is finished, restore your device from the backup you created in step 1. You should then have iOS 6, complete with your apps and information, up and running on your iOS device. If you have any issues, the Apple Developer Forums are a great place to start looking for help.