Remove Product subtotals

I would like to remove the product totals (Subtotal, Add-ons total, and Total) from the single product page. I saw that this issue was resolved on a different post however I would like to know if the following answer is referring to the theme’s css and how I would get to the proper CSS file to make the following edit.

“Yes, those line items can be hidden. Our recommendation is to use the CSS display attribute display: none; for the fields: zaddon_subtotal, zaddon_additional and zaddon_total of the Product Add-ons line items you want to hide and not display for the Product page”

The page I need help with: [log in to see the link]