If Apple's mobile phone is out of memory, you can delete some applications or video files to free up space, so that you can refresh the memory correctly, or upgrade directly through itunes. Please refer to the following steps for specific methods.

1. Turn on the Apple phone, connect the computer with the data cable, turn on the iTunes software of the computer, and press and hold the power button for 2 seconds.

2. Without releasing the power button, press and hold the Home button 10 second, and then the phone will be forced to turn off.

3. Without releasing the Home button, lightly press the power button 1 time, and hold down the Home button for about 15 seconds. The phone screen displays the information of connecting Itunes icon, and then enters DFU mode.

4. After entering DFU mode, the computer has voice and SMS prompts to discover new hardware, itunes prompts that iphone needs to be restored, click Restore, and iTunes automatically downloads the latest firmware update machine.