‘content header’ modification under ‘Description’ tab

You could try the Loco Translate plugin to change the text to your liking, or you could try some custom css:

#tab-description h2 {color:white}
#tab-description h2:before {content:"Package Description"; color:Black}

In this case, unfortunately the original text still takes up space though you can’t see it.

@lorro

Renaming Tabs
https://docs.woocommerce.com/document/editing-product-data-tabs/#section-2