[Magnumutz]

First of all, login to your AdminCP. Then, on the left menu, you'll see the "Styles & Templates" expandable menu, click on it until it expands, then select "Style Manager".
Now you will see all your installed styles. Choose the one to edit and on it's right side, there's a drop-down menu, where you have to choose "Edit Templates".
On the new page that appears, almost on the center of it, you'll find some selectable templates, scroll down to "Navigation / Breadcrumb Templates", now you'll see the same page but with new templates available for you to click on, select "navbar"... that's the one you need to edit.