Resetting a user password in Linux is pretty simple and is only a one word command: passwd
Login to as the root user or switch to the root user.
$ sudo su
$ su root
Now we can change the password.
Using the following will change the password of the root user:
The next one will reset the password of the specific user
$ passwd lyle
In each instance you will be prompted for a new password.
That’s pretty much it. There isn’t much else to it.