how to change the navigation of header?

I want to change the header navigation, for example: I want to change the "wholesale" to "about us"
but I chang it in EZ-pages, I add the Internal Link URL:index.php?main_page=about_us
but after that, I found the "about us" can't use, when I click on it, there is no use, and no redirection to about us page.
Could anyone tell me how to change it if I want to change the header navigation.
which files need to change?
Thank you for your help .
Alan

The picture doesn't help us know what went wrong with your navigation. Seeing your site live may help. We need more info about what your site has. Did you install the "About Us" page mod? If not, you don't actually have a page named about_us. Do you currently have a page with "about us" content? Creating an internal link to that page with the title About Us will give you an "About Us" link in whichever ez-page menus you have activated the link. Does the "Wholesale" link currently point to the page you want to call "About Us"? If so, you need to change the Wholesale ez-page title. Putting an internal or external link in that page will cause the page content to be ignored and it will try to redirect to the link address.

Hello Glenn,
I installed the template with ultimate SEO URL, and I am sure it is removed completely and I have restore the files, it is no problem.
my url is: https://www.jewellet.com you can check the head navigation.
and my question is:
when you click the Gifts, then the URl is
http://www.jewellet.com/wholesale-gifts-and-party-supplies_c23
because I uninstall the SEO add-on, so the page can't display
so I set it in EZ-pages,
Internal Link URL I write index.php?main_page=gifts

after I change it, when I click the gifts, there is no action and no link to gifts.

Hope I have make my question clear.
please help me.
best wishes

So this problem is caused by having uninstalled Ultimate SEO URLs. In that case, you need to ask in its support thread for help, as only someone familiar with it can advise how to complete the removal of its effects.