Removing paint? And any repair tips

Nail polish remover(clear,acetone based) will remove paint. It can do damage though so use with caution. If you get it on the good paint it will damage it and too much on the gypsum will soften it. If you do try it I would go very slowly and carefully. Fine grit sandpaper might also work depending on the area you’re using on. Less risk of damage overall but it can remove detail in areas that aren’t already smooth. Unfortunately I don’t know of any methods for paint removal that are completely safe.

Rubbing (isopropyl) alcohol will remove the paint from some types of paint pens/markers, if that’s what was used. I’d carefully try that first, and then move on to nail polish remover (acetone) if the alcohol does not work. Be careful, go slow, use it in very small amounts.