How do I take off the foil cover of a TI-84 plus calculator?

I am a junior in high school and I have a TI-84 Plus calculator, the screen of which has a few horizontal lines of dead pixels (the bag it was in was damp), but everything else works. I am trying to take the calculator apart in order to fix this problem, but I am unable to take off the foil cover. I have seen and read that there are supposed to be two screws holding the foil cover in place but I don't see any visible screws. Also, in other calculators of this same exact model the foil cover extends further, but in mine almost half of the circuit board is exposed.