Custom Image for Slider

Hey! at first, sorry for my bad English.

I want to change the slider image to custom image. I suggest that the Advanced Custom Fields plugin can help me, but I dont know what files (flex slider codes) i need to change for it.

Thank You.

This plugin will allow to use custom image instead of featured image for slider but it will still be associated/linked to that post. Slider code is located in extras.php as sparkling_featured_slider function.

More specifically you might want to look at this part of function which call for featured image inside post:

              if ( (function_exists('has_post_thumbnail')) && (has_post_thumbnail()) ) :
                echo get_the_post_thumbnail();