That does not show the 4 extra screws located on the upper side of the grill.
I got the 2 screws which you simply have to pinch to get them through. However, there are 2 other screws which are screwed into a sleeve which "explodes" at the tip so that it can not be pulled out. Argh, pulling won't get it out. The plastic is more likely to break.
i got mine of now and i removed 4 total i think and then i had to pull liek a Muther F*cker to get it off but now knowing what is holding down the rest of it i think you can push down on it and slide it out towards you to release it from the hooks/holders