RPM dial arm off

There should be plastic tabs around the edges that can be carefully pried off until the clear window can be removed. But often they will just get broken and you might not even be able to fix the dial anyway. It is usually easiest to find a used one at a junk yard. Depending on where you live, there might be a place that lets you pull the part out of a junked car yourself for cheap. Otherwise I would check Alliexpress, searching for a "Hyundai Elantra XD" or "Elantra 3rd Gen" to help narrow it down. The front fascia trim is not too difficult to remove after you locate all the screws holding it in (there are a couple of hard to see ones above the dials), but it takes a little practice to know how to pop the retainer clips out without breaking any of them. Which is where a junk yard helps as you get to practice on those without the worry. I would buy some plastic pry bars from Harbor Freight or Amazon (super cheap) so you dont tear anything up. They wind up being super useful around the house anyway.