Swapping/adding images/slideshows

Hi. Ive taken over this website and am finding it difficult to work out how to add new slides to an existing slideshow or even add a new slideshow one instead. The instructions say to add [meteor_slideshow] to the page. It already has this shortcode and I cant see how to change it from one slideshow to another when the shortcode is the same?

Also I can delete slides and limit the number to be shown in settings but when I add a new slide and increase the number of slides in settings the new one doesn’t show up.

What am i missing?

Thanks
Peter

The page I need help with: [log in to see the link]