These are the clarified instructions on how to put your iPhone, 7 and iPhone 7, plus into recovery mode? You may need to use recovery mode if you're having trouble restoring your iPhone using iTunes. Let's begin connect the device to your computer using a USB cable press and hold the sleep/wake and volume down buttons. At the same time, you don't release the buttons when you see the Apple logo keep holding down both buttons. Until you see the recovery mode screen, iTunes will pop up a message, letting you know that there is a device that needs to be updated or restored. Please see the text version of this tutorial for more details and remember to follow or subscribe to. I clarified for more Apple news, videos and tutorials.
Source : iClarified