size chart link entry

97 0 39

Hi, I'm currently trying to follow this guide:

I'm trying to put the first piece of code where it says, but I can't figure out where to place it. 

I'm trying to get it placed underneath Size: 36 on this page:

but i just cant seem to find the positioning on the product.template.liquid


this is the code

{% if product.options contains 'Size' %} 
        <a href="#size-guide" class="popup-trigger" data-popup-trigger="one" >
              Size Guide
{% endif %} 
If anyone else has any easier advice on how to add a size chart tab or pop up im very open to suggestions