On the first page of the thread you will find:
"Removing the clear cover exposes the tachometer/instrument faceplate material. At this point the tachometer needle needs to be removed. An instruction I read on the internet worked well: Grasp the hub of the needle between thumb and forefinger and pull up pretty firmly and steadily. The hub should come up by an eighth of an inch or so and then stop. At that point, twist the hub counterclockwise against its internal stop while pulling gently upward. It will slowly twist off. I've done this twice now without incident. (EDIT: Looking at the smooth needle shaft in the photo, I think there is a bit of magical thinking going on in this removal procedure. But it works.) To reinstall the needle, make sure to position it to read zero when the stem has been rotated counterclockwise to hit the stop. Then push straight down. The post seems like it could be damaged easily, so deliberate caution is required."