Hyundai Repair: 2004 accent stereo code and removal, radio code, center position

Question
Recently my battery went flat ,ive been informed that i need to remove stereo and recover serial number so that hyundai agent can give me correct code to enter into stereo to unlock.How do i remove from dash is there any secrets?Much appreciated

Answer
I was unaware that the 2004 Accent was available an anti-theft radio.  On the chance your radio's code system works similarly to the older radios, don't remove the radio yet.  Try the following:

Turn your radio off.  Then, while holding the band button in, turn it back on.  You should see a pattern of horizontal lines and maybe a number 1 in front of them.  If you let me know the positions of the lines and whether the 1 is present, I should be able to provide your radio code for you.  

The potential lines are in a 3x3 array.  So you can give me the positions like this:
Top row center position, middle row left and center positions, bottom row right position, #1 not present.