My original windshield has lots of scratches. I used Quixx scratch remover to remove them. The scratches are gone but in place I now have swirl marks from rubbing with the soft cloth that came with the kit. I decided to order a closeout tall windshield with vent from Dennis Kirk ($134 shipped). Found a youtube link demonstrating the steps in windshield replacement. Very clear and easy to follow:
I hope there won't be any problem when I actually install it this Saturday.