I fitted the rubber around the glass then sprayed all 3 sides of the rubber with plenty of silicone lubricant. Then gently pushed the glass into the frame. I found that even though I'd sprayed the rubber with lubricant, it would only push in about two-thirds. At this point I pushed the rubber into the frame (on both front and back) so it was in it's final position against the frame edge, and pushed the glass in the final third. I was lucky enough to buy a screen from another member who was selling. Sevens and Classics can supply heated screens and even fit them for you. Louis