Universal application with IOS 4.2 and Xcode 3.2

I'm developping Iphone application and I want to convert it to a univ开发者_StackOverflow社区ersal one. I found many tutorial that deals with this issue but they seems to be ancohérent to the new release of SDK and Xcode. As many said I think that making a universal application is so easy. Can you give me the necessery steps or a tutorial link? Thanks.

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I think you will find necessary information and steps in this tutorial

http://iphonedevelopment.blogspot.com/2010/04/converting-iphone-apps-to-universal.html

and as a side note you should be aware of converting an existing app to universal app

http://useyourloaf.com/blog/2010/4/7/converting-to-a-universal-app-part-i.html