I'm having problems modifying the left navigation QuickLaunchMenu, I'm working
on a template site and I don't understand what's the problem

The question is that I don't how to modify the text of the menu items in the
left navigation bar , because isn't a custom web site is a template then I can't
use the "modify navigation" option from

site actions --> site settings --> site navigation

I also tried to find the datasource QuickLaunchDataSource associated but I
could't

In the attached image you can see What I'm trying to modify.

If any can help me will be great ! the only thing I need is where is located the
datasource o a alternative way to do that without harcode the items in the
page.master