How do I update my IPhone 3S to a newer version so that I can access new version of IOS and ICloud?
Connect your phone to a computer with itunes installed on it, and update it to the current version of iOS. (6.1.3 at the time of my answer).
This is assuming you have an iPhone 3GS. Iphone 3G won't update to iOS 6.
You could simply read and follow the instructions in the article from which you posted the question. It provides complete and explicit instructions on how to accomplish the upgrade.
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