How to upgrade from any iOS beta software to public release

So I've been googling around... But no one has to right answer. What I get from googling is:

1. If my beta/GM build number is the same as public release, then when pressing "check for update" I won't get any updates
2. Otherwise, it should notify me that I need to upgrade
3. If it doesn't work, I need to go to apple.com to download .ipsw file and install it manually with option-click. I tried searching and going to developer.apple.com/ios but I can't find it. I'm a developer.
4. I tried going here: http://www.felixbruns.de/iPod/firmware/ but the build number for iOS 4.3 is different. I don't quite trust that website..

What do I have to do now to upgrade from 4.3b1 to 4.3 public release? Please help me

 

Yeah, but I thought there are more people here so I post it here...

I tried downgrading to 4.2, but turns out I do NOT have any single restore file in my ~/Library/iTunes/iPad Software Restores, so I got an error when I press restore in iTunes... This is also a mystery for me, does upgrading to a beta software deletes the restore file?

EDIT:

Checked out the developer forum. They said clicking restore should begin download of the public release. If that's not working then I have to download the ipsw file from somewhere. Those guys gave me a link to the ipsw file... Now downloading 597MB of file...