I have a 1998 Sea Ray 240 Sundancer and this is a camper canvas question. Everything is snap and zipper except for where it attaches to the windshield. The clear plastic windshield canvas has a black rubber strip at the bottom that appears to slide in to the top of the window frame, sort of like a tongue/groove track system. How do you get it started in the groove? There are no open feed ends on the windshield to get it started....Help and thank you.