I am trying to delete all content from my iphone so i can give it to someone else to use but it wont allow me to delete the content as it says "authenticating errors" or password incorrect or cannot connect to app store, when i tried to delete from my itunes it says i need to turn off find my iphone in icloud but i cant do that either due to authenticating errors, in my icloud settings it says icloud drive upgrading all the time...please help asap?