Help - Manual Sunroof loose at driver's side hinge, not release handle

[BoostAddict]

I notice the other day that I'm getting a lot of whistling from my sunroof. Its not that its not tight enough at the handle, its actually the front driver's side hinge that the glass rises up from. I can tell its loose cause there is play on that hinge and i can even depress it slightly when the glass roof is closed.

From the interior, I tried to remove the plastic cover (?) that seems to be covering this hinge, however, it was not coming off with moderate force, so I decided to stop before I broke something.

Does anyone have any idea how I could tighten this?

-Chris