Customer Image Replacing/Changing Plugin?

I am new to WordPress and I am in need some advice please.

A customer needs a way to change images on the website I am making, in a clean and simple way. They have a very limited knowledge of computers so going into the code or using WordPress is not an option.

Is there any Plugin’s that could help me? I have been using Google to try and find what I need but with no luck.

Thank you.