How to replace primary menu in a custom Page Template

In the members-only forum a user asks:

Hi

I’ve created a page template for a new section for a client’s site but want to also have a different menu. For the new page template I just copied page.php and renamed it then will style that, but how do I change the menu it uses?

Is this something you could do a tutorial for?

Thank you

wp_nav_menu_args filter can be used to conditionally change the menu assigned to primary (renamed as Header Menu in Genesis Sample) theme location.

Here's a sample custom Page template file having the code: