Is there a way to reset the password from boot. The password was accidentally removed for the admin user and there is no way to use sudo or reset the password from gui.
I wouldn’t recommend it, but you can mount the SD card on another Linux system where you have root access, and then edit. The edits wouldn’t be simple unless you have copies of “/etc/” files “passwd”, “passwd-”, “group”, “group-”, “shadow”, “shadow-”, “gshadow”, and “gshadow-”.
If you have used JetPack/SDK Manager to flash from Linux, then there will be a “Linux_for_Tegra/rootfs/” subdirectory, and within that those files will exist. The problem is that on recent releases the accounts are added during first boot and don’t exist in those by default.
If you really want to save this, then you could install to a new SD card, run first time boot, and then copy those files from the SD of the system where you just added the accounts. You’d have to be very careful to maintain file permissions.
Unlike Windows there are no Linux tools to routinely change lost/missing passwords after losing the admin account.