A friend has bought a new iPad and given me his old one. He wiped as much as he could off of it. What should I do to begin using it? I have a Macbook Pro and a iPhone but don't want to sync any of them with the iPad. Someone told me I need to totally wipe the iPad clean and load a new OS on it. How do I do this? Right now it says it's "Up to date" running iOS 9.3.5. Yes, it's an OLD ipad... thanks for you expertise and assistance.