You need to pull of one of the plastic end plates and then the circuit board will slide out. If you have short fingernails you can grab onto the corners and just pull. Alternatively use a thin screwdriver to lever it open at the corners. Please see the attached picture.
However, this is a very complex double board assembled by a robot and is very difficult to repair. You can try to solder back the AV connector. If you do not succeed then you will need to buy a new device.
[image|1868709]
Kind regards
Chris