So you are now the new Linux user and during the install you set a password, but now you have a need to change it. If you run a headless sever (no desktop) you may be interested in this little bit of info.
You can use the passwd command to change your password, and, as a system administrator, change the password of the root account, or another user in your Linux system. The syntax is as follows:
In your terminal (desktop system) or ssh type
passwd and you will then need to enter your current password followed by your new one twice ( the second time is confirmation)
If you are a root user you can change the password of another account by typing: