I read this answer in the forums regarding restoring an iTunes/iCloud backup when migrating to new phones: https://forums.developer.apple.com/message/30467#30467
When I hit option-click Restore iPhone, it tries to locate an old backup. I have a backup through iTunes (on the computer, not through iCloud), how would I go about the restore? I am restoring iPhone 5 backup and purchased an iPhone 6+ (I already disabled Find my iPhone and had the pop-up update as your described and am updated to iOS 8.4.1). My only suspicion is that I was on the latest developer update on my iPhone 5 (iOS 9)? Do I just need to update to iOS 9 in order to restore my iPhone or is there something else I'm missing here?