Was painting a bedroom that is hardly used when I discovered old leak damage. It had basically gone around the whole perimter of window so I removed the wooden stool and drywall on the top side and after getting tested for mold and because the frame was still sound decided I didn't need to go any further but I want to case the return in wood. Problem is there is a bit of a lip around perimeter of window that is drywall. My thoughts are to carefully remove the drywall to where it is all somewhat square again. The window had never been insulate either so I need to add insulation and a backer rod. I am better at woodworking than I am at drywall....just want to go the eaisest route even if it takes the most amopunt of time.