Windscreen scratches can be repaired at home but it depends on the severity of the scratch. Autoglass suggest running a fingernail across the scratches - if your nail catches in the damaged area then it requires professional repair, but if it feels smooth under your nail then it can potentially be polished out.

We would recommend finding a dedicated automotive glass polish and a soft microfibre cloth, and after ensuring the area is clean, slowly working across the scratches with the polish before buffing off with another clean cloth.