Hi!
It’s actually the content that has a 30px bottom margin. I don’t recommend changing the CSS files, as you might loose the changes on update.
Instead try to add the changes to a custom css file in your theme, or you can use the custom CSS section on the plugins theme options panel.
Anyways, the code that you are looking to add is something like:
[html]
.slick-slider {
margin-bottom: 0 !important;
}
[/html]
Try to add this to the custom CSS section, or any of your themes CSS files.