Hello,

Do you mean the slider or the page header images?

Anyway this is the link in the documentation how to change the slider images: https://codeless.co/documentation/main.html#codeless_slider

and this is the section on how to change the page header image:
https://codeless.co/documentation/main.html#default_page_header

Also you can change the page header and overwrite the default page header by edit the page itself in the page header options:
https://codeless.co/documentation/main.html#create_pages

Let us know.

Regards!