Re-Wiring 1975 Plymouth Duster

Get a factory replacement harness. Pull the speedo unit and glovebox liner, and get to it. Get some die-electric grease and grease every connector. It isn't that bad and is actually a relaxing job.

Pulling the front seat is optional.
I have pulled the front bench seat and rear seat, next im going to pull the glove box and instrument cluster. Im hoping that will give me enough access to see what im doing without having to pull the dash. Should i pull the old fuse block and snip associated wires first to have a "clean" start or go cable by cable replacing existing wiring from component and old fuse box with new wiring to component and new fuse box? Thoughts?