If you got the CD/Tape Clarion radio then you need to remove one screw at the top of the radio, and 2 screw on the ash tray (remove the ash tray first). Then the radio is attach with 4 screws and you might need to cut a plastic strap holding the cables together and not allowing you to remove the radio completely.
I have the '02 Clarion just Cd player. I pulled my radio out once and found that you have to remove the dash molding around the radio (just a few screws) then the radio unscrews and pulls out. I ran into some space issues due to my manual transmittion, there's not a lot of room to actually pull forward but it can be done with minimal finageling.