You would grab the html between the <body> tags and either add it to a snippet then include the snippet in the page template to keep things organized, or find the relevant page template and add it directly.
The Css and Javscript would either need to placed into the relevant html tags (<style> and <script>, or added to the relevant CSS and JS files that are already a part of your theme.
Some themes also have a 'custom html' section where you can add such code.
If you want this customization you can contact me at paull.newton+shopifyforums@gmail.com
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