Alhambra radio change

[nickturner]

I am replacing the radio in my 1998 Alhambra (origional fell apart - mainly due to kids) and I have the adapter cables. I have now been told that I need to connect the adapter cable to the amp. I would like to (need to!) know how I get to the amp and connect this cable.
Does anyone know where it is and how I get to it?

Thanks

Nick