How to get into the vents

I dropped something down one of my ac vents, is there anyway to get into there and what is the best way?

I can comment on the older style dash vents.....they are held at the ends (top and bottom or L and R side depending on how they're oriented) by little plastic swivel clips with small posts on them. To pop them out, insert a thin blade or screwdriver into the center of one of the ends and push down to disengage the post from the housing and pull one end of the vent out. The other side will free itself.

It's a bit hard to explain, but once you see how they are held in you'll know what I'm talking about.

Jeff

I should have been more specific, I can get into the vents but then there is a tunnel through there and it dropped down it. It is the middle left and its a 2000