I have an iPad 3 with iOS 5 on it, and at work we need to test something on iOS 6. Is it possible to update from iOS 5 to iOS 6? Doing the automatic update wants to go straight to iOS 7. I have an iOS 6.1.3 .ipsw file, but when I hold shift and click 'update' in iTunes 11.1.5(5) it just wants to install the latest version of iOS 7. Is what I want to do possible? Thanks in advance.