iPad 2 / ios4 upgrade

Hi there, I'm trying to upgrade an iPad 2 / iOS 4 to iOS 7 but don't want to go beyond 7. Anybody knows how to go about this? I have tried several ways but it all comes down to using the "software update" option in settings / general / about, which isn't there in iOS 4, appeared in iOS 5... Can it be done?
I'm worried that if I go ahead with the only upgrade option available, that is ios9, it will take me there directly, with no way to downgrade to iOS 7...
Any help greatly appreciated, thanks!