Hi I need to update my iPad 2 and iPhone to 8.4 from 8.3 but from iTunes it will only update to 8.4.1 and I want to keep JB. If I download the 8.4 ipsw file can I update to 8.4 or will I need to update to 8.4.1 then downgrade to 8.4?? Never done it this way before. Thanks for the help!!