Heater hoses just run right from the alt. bracket to the heater core at the firewall. Should be hose clamps at both ends, a simple swap and a system top-up and bleed.
I always do a spill-free job when servicing something higher up in the cooling system. I remove the rad cap and put my hand over it, and take compressed air, and remove the bleder screw and put it to the hole. It will force the coolant into the overflow tank temporarily, and when you're done, go the opposite way with it and it will put the coolant right back in the radiator.
