Replace header phone number with my own code

I am trying to implement Google Analytics code to track addword calls, I need to replace where the phone number is in the very top of the header.

I have a Child theme and I have the help-main-menu.php accessible in it. I don’t know how to replace the phone number area with this code:
<span class="number">1-800-123-4567</span>

I want to remove your code and add this in only, replacing what you have there.

I figure i need to do something with this code:

<div id='header_meta' class='container_wrap container_wrap_meta <?php echo avia_header_class_string(array('header_social', 'header_secondary_menu', 'header_phone_active'), 'av_'); ?>'>

and change the header_phone_active to my html, but I’m not sure how if its possible.

Thanks