What will it take to get this scratch out?

A lot of labor hours, along with a professional glass restoration system, I have seen panes that large resurfaced and it looked all wonky, probably easier to replace and install an anti graffiti film afterwards, imo it should be covered under insurance.

That appears to be acid etching done with a pin. Glass Renu specializes in removal of those. They give great support and training and will support you through the process.
Call me to order one of there systems 865-310-0728

Um no its not how its done, you get a rock from the train tracks and that will do it, its called a “scratchie” in the graffiti community, young hoodlums are not running around with pins and acid etching kits, they just pick up a rock.