Displaying Testimonials / Changing current id

I have recently been tasked with improving the company site, and a big part of that is to display our client testimonials in a more pronounced fashion. I am unfamiliar with this plugin (and relatively new to web development as a whole) and am having trouble understanding how to go about enacting change. The application of the plugin as it currently exists is a simple text box which contains the following: [egpr_reviews id=”6653″]. This yields a single review with navigation arrows on the right-hand side.

I don’t know where this ID# was generated and I don’t know how to make adjustments to this text in a way that produces any meaningful alterations to my site. I have been able to find instructional video to help me use most plugins that the site currently uses, but have not been able to find anything to help me with Everest.

Any help as far as effectively navigating this plugin would be appreciated.

The page I need help with: [log in to see the link]