I replaced the rotting rubber screen gasket on an Intel MacBook Pro yesterday. I should have taken a picture of the process, sorry.... But you can see the completed job above. It looks factory new. There are some videos of this replacement on YouTube, but in my opinion they are all bad, i.e. they use metal tools around the glass screen, or push the gasket in corner to corner, causing it to stretch.
The first step is removing the screen and then removing the old gasket. For me, the most difficult, as in tedious, part was getting all the rotten, liquified rubber from the old gasket out of the screen. It basically had turned into rubberized goo. You'll need a pick or some kind of scraper. I used only plastic and wooden tools, such as a tooth pick, or a plastic spudger. This process took an hour or so and I had a sticky mess.
When you fit the new gasket, the key to getting the screen gasket to fit and not stretch, or you'll wind up with about a centimeter of slack that you cannot seat into the grove. I used 2mm double sided tape to secure the bottom strip. Then I attached the corners. Once all four corners and bottom were secure, I attached the middle points between the corners. You can just push the gasket in with your fingers, and you will feel it lock into the grove. At this point, I just kept dividing the loose sections in half, until the gasket was installed all the way around. Do not work along the gasket, i.e. from corner to corner, as you will just stretch it. Overall I found the process to be pretty easy, but then again, I mess around and repair lots of stuff, so it might be more difficult for someone who doesn't do much repairs, or isn't comfortable working on their laptop. This was not an early-intel MacBook (mid 2015), but I posted it in this forum, as more members are inclined to do their own repairs than in the modern- forums and the process on an early Intel would be identical. For those curious about the screen shot, it's single-booting Debian 13 Trixie.