factory cover plate over radio opening?

[lurch115]

okay so i resently bought an '84 1/2 ton 2wd Chevy Short Box that is all original with 61,000 miles on it....and want to put a factory radio in it...what i was wondering is if anyone knows how the cover plate where the radio is supose to be, is supose to come off.....i was just thinking it was clipped on there... but i don't wanna break it seeing as it is an original OE part...any input would be great...here is a picture of the dash where the radio should be...

oh, and the second picture is the passager side of the truck....the truck in the background is the truck in my signature...the motor is soon coming out that and going into the new one...