How to wire into a cigarette lighter & how do the vents on the armrest come apart

[A210AMG]

Hello


My rear armrest DVD arrived, and seems quite good.

I will have a go at installing this, the mount looks easy enough and it comes with two leads to power it, a standard cigarette lead that just plugs in or this one...

Now I wouldn't need the RCA connecting up but what do I connet the black and red ones to near the armrest? this would look neater but I don't want to blow something up attaching leads to this and that.

Also does anyone know how this comes apart? (the air vents, ashtray) so I can see what wires are behind this.

thanks in advance