Power + pin 9 at the door pillar connector both sides go to fuse f56 jcase should be 30A and either yellow or pink.
Both sides pin 12 are grounded at the 8mm chassis ground bolt on either side of the foot well you'll see a bunch of wires grounded just connect them to that.
Pin 10 passenger bridge to pin 10 driver
Pin 11 passenger bridge to pin 11 driver
I can't really see an easier solution, it's only 4 wires. A loom might be the full dash loom and in that case it'll be a big job.
Have a look at the f56 fuse, see if you have upper spade which you will and lower spade which might be there or might not, if not then you are correct and you don't have the correct level loom.
Did I say it's only 4 wires though?
All you need are the pins that push into the door connectors, and then a length of cable to bridge them over.
it is listed as 1.5