IPSW Files for restoring can be found at http://imzdl.com/ios.php
The app to find your UDID can be downloaded at: https://itunes.apple.com/us/app/udid-sender/id306603975?mt=8
If you prefer, you may register here also: https://docs.google.com/forms/d/1iysEkb28DZpNzwsuABXGav9I8eCYRYqUy9uEIok_nig/viewform
Use betas at your own peril! It is pre-release software, but I have full confidence you are brave enough to take the leap.