Minor amount of coolant on passenger floorboards ('68 cuda, '94 360 mag)

67mopr said
My 67 Barracuda did same thing. I very carefully loosened the clamp on heater hose and slid it up closer to firewall. So far so good...

I wasn't the one to do the replacement last time. Is it something that requires dash out in our cars, or can it all be done from underneath?