Updating and using the iOS 5 beta will be done at your own risk. Please be wary of the consequences and risks of using a beta firmware.
Today, Apple has released beta updates for all their enterprise products: iOS 5, iTunes 10.5, Xcode 4.2, and AppleTV. With the exception of iOS 5 beta 4 and AppleTV, all the other applications were updated to support the newly released iOS 5 beta. According to the release notes, this update should bring some much-needed improvements and bug fixes.
Just like iOS 5 beta 4, you can download it over-the-air. However, to do OTA, you must do this first on your device:
Settings > General > Reset > Erase All Contents And Settings
This will erase all the data on your device - make sure to backup first before doing this (if applicable). From here, you can use the OTA feature on iOS 5 beta 3+ firmwares.
You can also go the "original" route and just install iOS 5 beta 5 with the IPSW file. Make sure to do it in this order:
- Backup/sync your device on iTunes 10.5 beta 4
- Restore your device to iOS 5 beta 5
- Update iTunes 10.5 to beta 5 and sync your backup with iTunes, or even iCloud
All supported devices for iOS 5 beta 5 are listed in the picture below:
Remember, as discovered on iOS 5 beta 4, the OTA update detects components on your device if jailbroken and will refuse to update. In order for you to upgrade from a jailbroken device, you must restore to your current stock iOS 5 firmware, and upgrade via the IPSW or OTA.
To download the IPSW file for iOS 5 beta 5, or any of the other above released betas, visit the Apple Developer site. You must have a registered developer account to have access to these beta downloads.
Sources(s): The Next Web, Apple