If it is a full loom then it would be a nightmare as it would be a dashboard off job and disconnect everything electrical and then try to remember where all the connections go.
A part loom would be easier, or just patch in the part of the loom you need to.
Regards the mirrors, I would check first that the connections and loom aren't already there. It is often easier and cheaper for a car manufacturer to use a common loom, so the connections may already be their. You would need the mirror switch and a new instrument binnacle cover as well.
I have the switch and mirrors what is this misterious instrument binnacle you speak of?
This is the bit. It goes in front of the intruments, just behind the steering wheel.