Removing the radio???

I know this might sound like a stupid question to all of you, but I need to know how to remove the radio without breakin' anything. I just bought a black 2000 ES v6 yesterday and the dealer said he'd replace the battery, and I know that dealers never lie (yea right) but the car died as soon as I got it home. I got a new battery but now I need the serial # off the top of the radio to get the radio code. I think there's a screw in the back cuz it won't come out, and I don't wanna force it. If there is a screw could someone tell me how 2 unscrew it. And please use small words cuz I'm only 16 and don't know much bout cars yet. I'd appreciate any help.
Thanks in advance