Upload the gallery-stacked-slideshow folder to the /wp-content/plugins/ directory.
Go to the Plugins page of your WordPress administration area and activate the plugin.
Create your Gallery by clicking on Stacked Gallery in your administration menu and selecting Add Gallery. Create a gallery for Gallery stack slider.
After create a gallery. upload images for that particular gallery using tab Upload Images
Go to your post/page and use TinyMCE button for adding GSS to page/post content.
for demo please click here