Steamdeck reset sudo password
This are the steps on how to reset a forgotten sudo password. You will need a keyboard attached to the Steam Deck to enter the commands easily -
While the Steam Deck is powered off, hold the the 3dots (QAM) and turn on the Steam Deck.
The recovery menu will appear. On your keyboard highlight the 3rd option - CURRENT (OS Boot Menu) then press enter.
The GRUB menu will appear. Highlight the 1st option - SteamOS then on your keyboard press e to edit the boot options.
Press down cursor on the keyboard until steamenv_boot is highlighted. Press end key to go to the end of the line.
append the command to end of line - init=/bin/bash
Press CTRL-X to boot!
Enter the command - mount -n -o rw,remount /
Enter the command - passwd deck
Enter new password and retype the new password.
And finally enter the command - reboot -f
sudo password has been reset! You can now boot to desktop mode and use sudo commands using the new password!