Adding and Deleting photo images to the home page

I have inherited the Website and the creator is less than helpful to make changes and updates. Been at it for a few hours, learning the ins and outs of the website. Have not been able to figure out how to add a photo ( that I have ready for input) onto the homepage of the website. Some of these photos need to be removed as well. Not sure how to do that either.

Trial and error is a frustrating way to learn.
Looking for direction on completing the task.

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