Having issue modifying theme code to replace logo URL - php

Question

Using WordPress on the default twentysixteen theme. This is a code issue not a theme issue which is why I'm posting it on SO. I have a feeling I'm just doing something simple wrong but I've searched and figured out what code I need to change but it seems like it's not making the changes as expected.
So what I'd like to do is change the LOGO that is currently going to the website "home". I'm talking about the front end logo at the top left that i'd like to go to one of my other sites which has more relevant information.
But when I change this code:
<div class="header-image">
<a href="<?php echo esc_url( home_url( '/' ) ); ?>" rel="home">
<img src="<?php header_image(); ?>" srcset="<?php echo esc_attr( wp_get_attachment_image_srcset( get_custom_header()->attachment_id ) ); ?>" sizes="<?php echo esc_attr( $custom_header_sizes ); ?>" width="<?php echo esc_attr( get_custom_header()->width ); ?>" height="<?php echo esc_attr( get_custom_header()->height ); ?>" alt="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>">
</a>
To:
<div class="header-image">
<a href="http://external-website-here.com">
<img src="<?php header_image(); ?>" srcset="<?php echo esc_attr( wp_get_attachment_image_srcset( get_custom_header()->attachment_id ) ); ?>" sizes="<?php echo esc_attr( $custom_header_sizes ); ?>" width="<?php echo esc_attr( get_custom_header()->width ); ?>" height="<?php echo esc_attr( get_custom_header()->height ); ?>" alt="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>">
</a>
It doesn't seem to be affecting where I'm redirected when clicking on the logo image. In other words it still goes to the home_url it seems instead of the external site.
Any suggestions are much appreciated.
Additional Information: No caching is enabled, tried other browser/devices to make sure it's not a cache issue.
Update: Even remove the entire code from my first code box it doesn't change anything on the front end. Maybe I'm modifying the wrong file? How do I figure out what file the logo code is living in?

Answer 1

You're looking at the wrong code.
You need to edit line 35 and 37 of the header.php, which I can see here: https://github.com/WordPress/twentysixteen/blob/master/header.php
This is because you don't have a logo, as far as I can tell anyway.
Update:
I've updated your site to work.
What I did was add function to filter the home url;
//functions.php (end of file)
/**
* Changes the url returned from home_url();
*/
function change_home_link($url, $path, $orig_scheme, $blog_id){
return 'http://google.com';
}
Then add and remove the filter in the header
//header.php line 32
add_filter( 'home_url', 'change_home_link' );
twentysixteen_the_custom_logo();
remove_filter( 'home_url', 'change_home_link' );
You could also just remove the twentysixteen_the_custom_logo() function and replace it with what ever you want.