Xcode cannot detect iPhone device running iOS 5.1
In addition to Shubhank's answer (and everyone else), remember that Apple's app store is where you download it. So it magically fits somewhere (developer dir) without rewriting Xcode.
You have to find it and replace your shortcuts to run 4.3 instead of 4.2. There are no prompts for either "open the extracted folder" or anything else. In case you're wondering why you open Xcode and it still doesn't find it. You go to the App Store and you notice that it says Installed, but there is never a link to figure out where, so you have to dig and hope comparing the creation times in the files.
(After that, it will offer to uninstall 4.2)
If anyone had a smoother time, please post how!
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