Wiring a Rear Power box in a Pajero

I have been asked to install a Waeco Power point box into the rear of a Pajero Diesel (recently superseded model). Being a Patrol owner, I am just looking for some guidance from the Pajero crowd, and I haven;t yet had the opportunity to look in detail at the Paj.

The box is similar to that currently being advertised on this site in the $1299 special. It comes with a dual core lead to run to the front of the car, and a lead to the ignition. It will be used to recharge a Waeco battery which will in turn power a waeco fridge.

So questions are:
1. Where is the easiest access through the firewall?
2. Is there a tunnel underneath the door sills for the cable?
3. Do the plastic Door sills just "lift up"?
4. Will there be a need to remove the rear wagon lining, and if so, how is it done?

Thanks in advance for any tips.

Cheers
Andrew