PDF Theatre Script/Score Clean Up

I'm a sound designer and typically I get scripts that are copies of the original in PDF format. The scripts have details in them that I don't need and sometimes they have page marks/black boarders, etc from the copy machine. I edit them by whiting out what I don't need using a PDF editor. I don't need to convert to text, I just need the messy stuff removed. It easy work and typically takes about an hour to do. I'd like to find/train someone that I can turn scripts over to get them cleaned up. Notice the attached documents, this is one page from a show I'm working on. The before document is typically what I see. The after document removes all the black boarders from the copy machine, the extra lines/marks on the page, and I also remove the "Stage Direction". The only "stage direction/notes" I would keep in the script are notes that relate to sound, i.e. "Thunder is heard" "Door bell ring". Scripts are around 150 pages. I use Nitro Pro and the "Whiteout" feature to delete what I don't want. You can use any tool that does the same.