Hi there, thats not possible because the slideshow has a "div" around which control the template width.
If you want to change it, please create an extra layout override and remove the div and then the slideshow can be 100% width.
Layout overrides
To customize the general theme layout, you need to override the /layouts/theme.php. To do so, create the /styles/STYLE-NAME/layouts directory, copy the file in there and start adding your own PHP code.
yootheme.com/themes/documentation/developers/customization
We are committed to help you with any type of support query, however we can't provide extensive help in terms of customizations. In general customizations may look simple but you will require solid knowledge of web technologies and programming skills to do them or hire a professional who can do it for you.