Thankfully it was an easy fix for you! A little paint touch up is doable.
We replaced all the windows in our house except 2 when we first moved in. It wasn’t until they took out the old ones and installing the new ones, that they realized one window was too short (6” too short) and so they left that DuPont humid barrier paper covering the window till they got a new one. Of course, this was the summer we had a thunderstorm almost every other day. One day, I thought for sure we were going to come home to a destroyed house because the storm was so bad. I was thankful everything was ok!
Anyways, we usually hire out any big projects (although that’s proven itself to not guarantee a job well done) otherwise, I will go on Pinterest or google for help.