How can I add older version of iOS SDK in Xcode 4.5

Question

I copied the iOS 5.1 SDK here:

Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs

But, I stil

Answer 1

From the terminal, run this command, then restart XCode:

cp -r /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.0.sdk /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/

Note, substitute 'iPhoneOS5.0.sdk' with the name of whatever SDK you're interested in copying.