Whether it's highlights or text blocks, you can delete any notes that no longer apply:
Tap on the note you'd like to remove to select it and see a trash can icon pop up
Tap the trash can icon to delete the selected note
If you're using ProductionPro on the Web, the trash can icon will appear top right corner of the document - right under the search icon.
If you're using the ProductionPro iPad app, the trash can icon will appear right above the selected note. You can also use the eraser tool in the annotations toolbar to erase your note. If you want to remove an note you just made, you can also use the undo button on the annotations toolbar to do so.