how can you take the faceplate apart? i want to clean the inside screen and i cant completely get the faceplate apart..i took the back 4 screws off and pried most of the circuit board from the front piece but its still stuck around the rotary **** and it wont come off, and im afraid to pull too hard so i wont break it..anyway the model is CDA7893, if anyone knows how to take the faceplate apart let me know..thanks guys