It pops up rather easily, I didnt even want it to, but when you try slipping sandpaper under it it will most likely come up on its own. I'd say being careful around the needles is the most of your concerns, make sure they don't come out. They shouldnt but just take your time, these are very delicate instruments; hence the glass covering.
BTW, any consensus on what works better - nail polish vs. sandpaper, or a combo of both?
Originally Posted by WiCKedReX
Doi I need to lift up the gauge to slide under the sand paper? I don't really get what you mean when you said there is a black ring under the gauge. I don't want to pop that up and break something.
You are lifting up the thin plastic covering and sanding under it:
There is a black plastic ring that holds the thing "face" of the gauge down. (the red ring above)