I have a 09 Grandvista, so I dont know if there is any difference in design. Here is how I do mine.
remove the six screws, then on the left side of airbox, there is a brass plate that runs from bottom to top of airbox, just remove the 10mm bolt on the bottom of plate, You do not have to remove the upper one that is behind the panel., Use a long socket or a extension so you dont scratch the variator cover. Here is some pics. You also do not have to remove the clamp for the rubber hose, the air box will just hang out of the way so you can remove the screws for the filter.
remove this one
do not remove this one, the plate will come out attached with the air box cover
Note, when you reinstall the air box, make sure the brass plate, (near the top bolt) goes behind the black body frame bar, not in between it, It must go behind it. Put the air box in on a angle so the brass plate goes in behind the black frame bar. Look at it before you remove air box and you will see what I mean.
Good luck, hope this helps.