Приблизительно так
<?xml version="1.0" encoding="utf-8"?>
<modification>
<code>articul to product</code>
<name>articul to product</name>
<version>1.0.0</version>
<author>SlaSoft</author>
<link>SlaSoft</link>
<file path="catalog/view/theme/oct_deals/template/product/product.twig">
<operation error="skip">
<search><![CDATA[{% if oct_deals_data.product_model is defined and oct_deals_data.product_model == 'on' %}]]></search>
<add position="before"><![CDATA[
{% if sku is defined and sku %}
<span>{{ text_sku }} <span class="light-text">{{ sku }}</span></span>
{% endif %}
]]></add>
</operation>
</file>
<file path="catalog/language/uk-ua/product/product.php">
<operation error="skip">
<search><![CDATA[_['text_search']]]></search>
<add position="before"><![CDATA[
$_['text_sku'] = 'Артікул';
]]></add>
</operation>
</file>
<file path="catalog/language/ru-ru/product/product.php">
<operation error="skip">
<search><![CDATA[_['text_search']]]></search>
<add position="before"><![CDATA[
$_['text_sku'] = 'Артикул';
]]></add>
</operation>
</file>
</modification>