how to remove "extra" pages link from my top navigation

Hi, Please help, I installed twenty 10 theme. I have created 10 page but all 10 pages link are appearing in top navigation.

My site is https://vrsoftwaresolutions.com

I only need 4 link on top navigation. When I open header.php file to correct this I didn’t find anything but the code belop

<?php /* Our navigation menu. If one isn’t filled out, wp_nav_menu falls back to wp_page_menu. The menu assiged to the primary position is the one used. If none is assigned, the menu with the lowest ID is used. */ ?>

<?php wp_nav_menu( array( ‘container_class’ => ‘menu-header’, ‘theme_location’ => ‘primary’ ) ); ?>

PLease help me to sort this issue..

Regards
Vikas