Take a pair of slip joint pliers, grab the rubber portion around the neck of the heater core port, and TWIST the hose. You don't need a Kung-Fu grip and want to make sure you don't crush the port.
Rotate back and forth until the rubber releases it's hold on the port.
Once it's free, pull it off. Allow the pliers to slip a little as you're going around the outside and trying to rotate the rubber around the port. It will release a little at a time until it finally breaks free.
The wrinkling of the rubber is what makes this work.
Sorry, this is the two connectors at the firewall, they are supposed to come off via a retainer clip. I am installing a kb supercharger and this is the first snag I have had.
It is supposed to stay together.
Thanks for your reply