{"smallUrl":"https:\/\/www.wikihow.com\/images_en\/thumb\/2\/25\/Update-iOS-Step-11-Version-2.jpg\/v4-460px-Update-iOS-Step-11-Version-2.jpg","bigUrl":"https:\/\/www.wikihow.com\/images_en\/2\/25\/Update-iOS-Step-11-Version-2.jpg","smallWidth":460,"smallHeight":345,"bigWidth":760,"bigHeight":570}2打开iTunes。如果你没有安装iTunes,你可以从apple.com/itunes/download上免费下载它。{"smallUrl":"https:\/\/www.wikihow.com\/images_en\/thumb\/d\/d5\/Update-iOS-Step-13-Version-2.jpg\/v4-460px-Update-iOS-Step-13-Version-2.jpg","bigUrl":"https:\/\/www.wikihow.com\/images_en\/d\/d5\/Update-iOS-Step-13-Version-2.jpg","smallWidth":460,"smallHeight":345,"bigWidth":760,"bigHeight":570}5点击“检查更新”按钮。4设备只能更新到7.1.2。Touch设备只能更新到6.1.6。{"smallUrl":"https:\/\/www.wikihow.com\/images_en\/thumb\/8\/8d\/Update-iOS-Step-14-Version-2.jpg\/v4-460px-Update-iOS-Step-14-Version-2.jpg","bigUrl":"https:\/\/www.wikihow.com\/images_en\/8\/8d\/Update-iOS-Step-14-Version-2.jpg","smallWidth":460,"smallHeight":345,"bigWidth":760,"bigHeight":570}6点击“下载并更新”。