need help removing part from column

hey guys, i need a hand with this. yesterday all my stuff locked up on me. the ignition switch and steering wheel wouldnt move. so i need to remove this plate (in pic looks like a sproket) so i can get to the ignition switch to remove it. the problem is, i have no idea how to get it off. i cant pry it with a screw driver.

this is off of an 87 iroc-z with a grant steering wheel.

and one other question, can i remove the pin the locks the steering wheel?

http://i63.photobucket.com/albums/h133/chevellecrazy600/0619091350.jpg

thanks everyone!

You need a lock plate compressor. Inexpensive and simple tool you can get most anywhere. It depresses the lock plate (there is a spring behind it), so you can remove the snap ring that is holding it on.

damn. i knew it had something to do with that little ring. thanks alot shoe!