you don't need to vent the sunroof panel to get at the screws or take it out, you only need to vent it to unhook the springs that hold the innerpanel to the outer sunroof. With some finesse you can probably unhook both springs with just one side up (two springs, one on either side). Use a long screwdriver to edge the springs off the metal brackets they grasp onto.

Once you get the springs off make sure the vent flap on the inner sunroof headliner is down and slide the inner headliner panel back. It unclips from teh sunroof and slides straight back on its own, leaving the outer sunroof of teh car inplace with all the gear right there. Then you just access the screws from inside the car (6 total, 4 in the front and 2 in the back), push the sunroof panel up, and remove it from the outside.

good luck,
rt