Once you decide on a harness it will come with a diagram sheet You'll need that plus the original diagram from the shop manual to map out your harness
Bart is right, to complicated to describe here
Best to get your ducks in a row.
Once you have it all , draw it out on a sheet of paper with all your components it will come together for you. Its not has difficult as it looks, and once you map it out it will be clearer. Fuse box protection is good idea.
For me it helped to map out each circuit separately.
