Heat not working

My 1992 Grand Marquis is not producing hardly any heat. I changed the therm. stat. I changed the anti freeze. The hoses to the heater core are warm .( in and out.) I,m not getting any antifreeze in the car. I don't think my heater core is bad. Any help would be great? Also, how hard would it be to change the heater core? Do i need to take all the dash out , or can i get at it on the right side only?

heater core could be plugged up. or a collapsed hose to the core.

I had the opposite problem. I wasn't getting cold air. It was an actuator behind the dash that opens and closes the blend door.