Work in a heated space and its easier to bend the plastic plus the glue works better. Start with a clean dry windshield edge. Having a friend help would be easier but I did it alone using blue painters tape. Attach center. Wrap around edge without gluing first. Use a heat gun or blow dryer to bend corners. Superglue every 6" from the center out, using blue tape to hold it. Trim ends. Don't tape over the superglue. If you are careful you can make it look perfect. I used a gel superglue and it worked well.
The original windshield on my 85 Cougar developed a crack on the perimeter. The crack was only about an inch long so I trimmed the whole windshield down about an inch and a half. The original trim piece was cracked too so I ordered this one. It works as advertised and I am extremely pleased with the results. just clean windshield edge with isopropyl and use a drop of super glue every few inches. Super glue is not included. Be careful not to get the glue where you don't want it as it will instantly cloud the trim finish and also cloud the windshield.
Would definitely buy again. Saved over $50 vs. a new windshield.