When you move the switch forward and backward the sunroof slides open and shut. When the sunroof is closed, rotate the bottom of the switch upward and rearward. The rear of the sunroof will open into vent position. Think of it as rotating the switch around a pivot point, instead of moving it back or forward. Looking at the side of the switch from the driver'* seat, you rotate the switch counter clockwise.
I am probably not describing this very well, but once you do it right you will see what I mean.