Does anyone have step-by-step instructions?

Prestige hard wired me a phone cable, but pulled it through between the silver veritical trim (next to radio) and the panel to the right of it - not only won't it reach my phone from there, the right-hand vertical trim piece won't sit back in position anymore.

If you look at the stereo, to the right is the vertical silver plastic trim, and above is the vent. If you follow the line down on the right hand side of the vent there's a gap between 2 other pieces of trim. I think I want the phone lead to come out here instead...

I can start to lift the right-hand silver trim, and this also loosens the tray under the satnav screen, but the left-hand silver trim refuses to budge, and I've no idea how to get behind the rest and towards the panel gap I'm aiming for.

Some step-by-step instructions would help!

It has to go back to Prestige anyway, so I might be able to wait and let them sort it out, but if I can have a DIY attempt, I'm willing...