Clean the scratched area with a soft cloth and a leather cleaner
Trim any loose leather fibers with small scissors
Apply a leather conditioner to soften the surface
Use a leather repair compound or filler for deeper scratches
Smooth the filler with a plastic spatula or card
Let the repair compound dry completely
Lightly sand the area with very fine-grit sandpaper if needed
Apply matching leather dye or color restorer
Blend the color evenly with a soft cloth or sponge
Seal the repair with a leather finish or protectant
Buff the area gently after it dries
Repeat the process if the scratch is still visible
Use a leather protector to help prevent future scratches