At the top of this website Wordpress answers is 6 menu items in the header
I need to change these on my website homesfriscotx.com how do I do it?
http://en.support.wordpress.com/menus/ - 1st result from google for "wordpress menus"
The implementation of menu items depends on your theme.
For newer or well maintained and updated theme it is usually implementation of Custom Menus feature. For the rest it could be anything from auto-generated list of pages to custom theme settings page in admin.