Rotating images in a template are managed with the Slider tool.  To use an image, you must first upload that image to the Slider Image Library (via the Image Library tab of the Slider tool). Once an image is added to the library, it can be added to any sliders.

To add/delete or sort images of an existing slider, go to the Slider Dashboard and click on the title of the slider you wish to change. From there you can delete any unwanted images from the slider. Deleting it from here only removes it from this slider, not the entire library and not from any other sliders that image may be being used in.
To change the order of the image rotation, click on the blue slider title on the dashboard. Then click the blue sort images button. You should then be able to drop and drag the images into the order you want.

To change the settings of slider (i.e. how quickly the images rotate or how they transition), from the dashboard click on the title of the slider and then choose the Settings tab then Edit Slider.

note: In most cases it is recommended that all images in any one slider are all the same width and height. If they are different heights the page content will move up and down to accommodate the extra height resulting in a poor user experience.