Defroster Vent Replacement 68 AC Heat controls facade.

If you drop the column down, you can unbolt the whole dash assembly and rock it back to get access up by the firewall. Just loosen the lower two bolts by the kick panel, remove the small bolts holding the dash frame up by the windshield gasket and just pivot the whole dash to get access. Disconnect the battery first of course. You shouldn't have to disconnect any wiring or cables just to install those vents. You may want to think about some new vent hoses though. Usually the factory ones are complete toast by now.