Hello,
We are theme support and we are responsible for files located in theme folder. wp-includes is the core folder of WordPress, why are you looking for any files there?
What area? Do you want to replace the image by slider? http://prntscr.com/sjagst You can use Revolution slider for these purposes (Appearance > Install plugins > install Revolution slider). Here you can find slider docs https://www.themepunch.com/support-center/
Regards