如何更新Joomla的主页？

I have one website in Joomla, but I don't have any Joomla knowledge but I have to update the homepage. I have gone through all articles but I didn't find out any homepage related article.

Below is our website link,

http://www.usinpac.com/

And I have to remove "DIASPORA LEADERSHIP DIALOGUES" and "US Presidential Election 2016" which is in just above the Main-Menu bar (near search bar).

I got that particular images to remove, but I have to remove the both images (also attached below for your reference) with links and other stuffs.

enter image description here

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These links are located in the header area of the template (rather than the main content) and are likely to be found in Module Manager. Log in to the back-end of the website and you should find these under Extensions -> Modules.