Clean the windshield thoroughly with glass cleaner and a microfiber cloth
Inspect the scratch to confirm it is only superficial
Apply a small amount of cerium oxide glass polish to the scratch
Buff the area with a felt polishing pad or soft cloth in small circular motions
Wipe away residue and check the scratch
Repeat the polishing process as needed until the scratch fades
Use a windshield repair kit if the scratch is deeper than surface level
Replace the windshield if the scratch cannot be safely removed