Dash side window defroster register removal

Question: How does one remove the side defrost/defog registers that are in the dash?

I would like to remove / clean / reinstall with the dash cap I just purchased but am not sure of how (or if) they release for removal without the dash pad out.

I searched with no luck but might be my terminology.

Suggestions?

Thanks!
-Stephen

BUZZ - I knew as soon as I asked I would figure it out. There are plastic retainers at the top and bottom. I used an allen wrench to get into the hole and release them.

Here's a pic if anyone wonders
http://i245.photobucket.com/albums/gg65/...CVent1.jpg