Extend existing widgets

Does anyone have any example code on how to extend existing siteorigin widgets such as SiteOrigin_Widget_Button_Widget or SiteOrigin_Widget_Image_Widget.

It looks like all the custom widgets that I’ve found all extend the base widget SiteOrigin_Widget and I’m interested in extending an existing widget to to change a few settings.

I have found the page here: https://siteorigin.com/docs/widgets-bundle/getting-started/extending-existing-widgets/ but it’s not much help because it doesn’t list any kind details regarding what files I need or any code context to know what I’m editing.

Any help would be appreciated,

Thanks!