It is very easy to install the downloaded files.
- Log on to Joomla! Administration page.
- Extensions -> Install/Uninstall -> Choose file
- Select the component downloaded and click Upload File and install
Now the component will get installed successfully. You can continue the above steps to install other Modules and Plugin. You can skip installing any of the module or plugin based on the requirement of your website. This is the
Extension Manager where we install the Component, Module and Plugin.
After installing the modules and plugin you got to activate the same from the Plugin respectively.
For more information about module manager please go to http://www.joomlatutorials.com/joomla-15x/joomla-15x-administration/module-manager.html