Here is a walk through on how to get that bloody thing off.
To get that needle off of your Guage, simply Vee groove an old Screwdriver.
Look under the face plate and you will see the base collar of the needle, that is where you need to fit the screwdriverm the Vee will fit snug around the pin shaft.
This is how I do my ones and it works great.
Once you slowly pry this up, the needle will come off, if you have a speedo that the bridge under the plate is hard to get too, simply undo the 2 screws on the plate and lift the face plate up a little.