My Account nav tabs

I’d like to add more functionality to the profile and project pages (like digital downloads etc.) by editing the css and the corresponding HTML of the nav tabs  labeled “My profile” “edit profile” and “Paypal details” buttons that appear on the my profile page (same for project page) of the template. I’ve scoured the templates source code and could not fine a way to edit these buttons (or add new ones). Any help would be greatly appreciated :).