You can modify the order of images to your already created slideshow. Follow these steps to do so:
1. Select the slideshow which you want to modify, and then click ⛭ to open slideshow properties.
Tip: You also can reorder images by clicking Element settings on the properties toolbar.
2. Select the image you wish to reorder and drag it to the place you wish.
3. When you're done, click the Update button and save your page!