As a regular (non-root) user, you can change your own password.
You can also customize your environment by modifying the configuration files
in your home directory; see the Configuring Your Environment chapter.
Changing your password
To change your password, use the passwd utility. You're prompted for your current password and then for a new one. You have to repeat the new password to guard against typographical errors.
Forgot your password?
If you forget your password, ask the system administrator (root user) to assign a new password to your account. Only root can do this.