I have an '01 civic, and to remove the radio bezel, there are 2 deep plastic tabs on each side and then 3 tabs on top and bottom. They are really stuck if they have never been removed before. If you use a butter knife, you can dig down there pretty far to twist it out without damaging the plastic surrounding. Not sure if it is like the '01 but should be close. They did a redesign in '01, but I don't know how extensive.
By the way, are you just trying to remove the radio, or the entire bezel with AC and heater controls too?