You can replace screens yourself. It
is easy to remove. For most window screens, you just need to pull down two pins, and the screen will pop out. You will need to buy a roller tool. Don't go cheap with tool. Otherwise, you'll have a hard time to to press them in. I changed 48 windows screens myself, and had no issues. If you have someone who hold screen for you, that will be ideal. Otherwise, you may have a hard time to control tensions. Also, you may want to wash frames as they are probably very dirty. I cleaned mine.
Good luck!
Alex