Sand the guitar using water-soaked sandpaper.

Start with 600 grit sandpaper, follow it with 800 grit, then 1000 grit, then 1200 grit and finally 2000 grit.

When you feel less resistance while sanding, it is time to move on to a higher grit sandpaper or finish sanding.

Do not press hard while wet sanding. Use a light touch to ensure your guitar is not scratched.