Where do I edit the GK Image Show

This may sound dumb but I can't seem to find where to edit the GK Image Show Slider Images. I need to change the slide images. Could some direct me where it is??

You can edit them in widgets (appearance->widgets) -> header area -> GK Image Show.
It points originally to:
slide1,slide2
those are coma separated names of photos in Media Library. Just add new images to Media Library, attach title to them (do not use spaces in slide title), add caption, description, alternative text (that is used to link image to subpage)