1. Boot/start your Kali Linux system and let the GNU Grub page appear.
2. On GNU GRUB page, press down arrow key to select “Advanced options for Kali GNU/Linux” and press enter.
3. Select the second option, Recovery mode by pressing down arrow key and press Enter key to go to recovery mode of Kali Linux.
4. Now, edit just read-only mode (ro) to rw (write mode). Also add init=/bin/bash like below screen then press F10 to reboot the Kali Linux.
5. After rebooting, Kali linux system will open below screen with option to reset Kali Linux password.
6. Now Reset root password of Kali Linux system, type “passwd root” and press enter. Now type new password twice for the root user. After password is changed, you will see the message “password update successfully”. Now reboot your system and log in to your system with new password of root user.