I redid the cluster in my 65 Dart. It is fairly easy to remove but the screws go into plastic so be careful. I wrapped the split plastic posts w/ nylon tape and epoxy to fix them. The regulator is in the fuel gage and smart to replace with an external electronic one. A guy on ebay sells them for ~$25 w/ good photos.
While you have the cluster out, sand all the connectors, including bulb contacts, and coat w/ silicone grease. Re-soldering loose pins on the circular connector is a common repair. I used LED dash bulbs which look nice and should last forever (ebay).
I went further and removed the plastic lenses and polished. That isn't easy since you must drill the "welds" and epoxy back. I also had all the plastic dash pieces chrome sprayed (Sacramento Chrome $110.). Might as well go whole hog.
