How to restore iPhone X in DFU Mode

• The data on your iPhone will be totally erased if you use DFU Mode Restore. As a result, make a backup of your iPhone before proceeding with the DFU Mode Restore.
• Connect your iPhone to your computer and launch iTunes.
• Press and hold the Volume Up button for a few seconds, then press and hold the Volume Down button for a few seconds.
• Press and hold the Side button right away (Power button).
• Continue to hold the Side button while pressing and holding the Volume Down button when the screen goes black.
• .After 5 seconds, release the Side button and continue to press the Volume Down button until your computer displays the message 'iTunes has found an iPhone in recovery mode.'
• Release the Volume Down button immediately, and your iPhone should now be in DFU Mode (Black Screen).
• Click OK on the 'iTunes has detected pop-up' on your computer, and the option to Restore iPhone will appear. To begin the process of restoring your iPhone, click the Restore iPhone option.
• Quickly press and release the Volume Up button on your iPhone.
• Next, quickly hit and release the Volume Down button.
• Finally, hold down the Power Button (ON/OFF) until the Apple logo appears on your iPhone's screen.

Read More: How to factory reset your iPhone X (master reset)?