Modifying Seperation Line in Sidebar-Widget

Hi,
I have a plugin that places tax and shipping costs directly below every product in the sidebar widgets for related products e.t.c.

The seperation line from woodmart is inside the product <li> and the tax and shipping info is outside so the seperation line is not needed and is confusing, so i’d like to modify/remove it.

How can this be done?

regards,
Sami