Tach Glass Foggy

Fortunately, I'm getting to some very minor items I'd like to take care of! One is that the the glass on my tach is very foggy. It looks as if it needs cleaned on the inside. All my other gauges are very clear (other than the typical foggy plastic clock cover).

Is there an easy way to take the glass of the tach out to clean it, or does this require a major dismantling of the gauges?

Also, any ideas on clearing up the clock would be great too. I've tried a Macguire's plastic fine scratch remover, but it didn't help much at all.

Thanks!