Remapping is done simply by selecting from a list of drop down options. Select from automatically pulled attributes or WooCommerce attributes.
To remap a Custom Product Attribute or an attribute not in the list, click the [open advanced commands] link to display a text box. Type the following:
mapAttribute [woo-attribute] as [merchant-attribute]
[attribute-name] is that found in the drop down box
[woo-attribute] is the local attribute slug (OR exact name of a custom field) and
[merchant-attribute] is the desired merchant attribute.
For attributes with spaces, enclose it with double quotes.
For example, to remap your own WooCommerce “my-title” attribute to Google’s g:title attribute:
mapAttribute my-title as g:title
Please see this guide for more information and examples: Attribute Mapping.pdf