Removing stereo surround on phase 1

[jamesbeaumont]

Hi guys. 2 questions! Currently in the process of removing a double din stereo from my 172. I have sourced the standard parts to go back in but realised the silver plastic surround is screwed on behind the dash - does the whole lower dash need to come off to get to the screws?

Second question. When I plug in the standard stereo I get nothing on the dash display and just a few beeps when I prod the stereo buttons. Do I need to enter a code first?

Thanks in advance