[Theme Horse Support Team]

Hi ciaranhyde,
Just add the images with the same name as we are using in our theme. But you need to create a child theme to bev safe from the lose of data before making any changes on it. After creating the child theme and then activate the child theme.

IF you are not getting the images and still original image is displayed then you have done something wrong. So you need to hire a developer to fix the issue.

Thank you!