How do you get rid of the News Flash or other modules?

From Joomla! Documentation

Any Joomla! Module can be disabled from the Module Manager. To do so,

  1. Log in to the Joomla! back end and navigate to the Module Manager.
  2. Locate the desired Module (for example, News Flash).
  3. Click on the icon next for this module name in the "Enabled" column. This will toggle the Module between "enabled" and "disabled".