The best way would include wetsanding and machine polishing afterwards to level out filled-in area. If you don’t have the tools or experience to do this however, then I’d just pick up some touch-up paint from your dealership, prep the scratched areas with Isopropyl Alcohol first to remove any waxes or sealants, and then when using a fine brush (I use ultra-fine felt brushes from the hobby store), put a very light coat of paint in the scratch. Allow to dry, and keep repeating the process until you’ve built up a good level of paint. I hope this helps.