Best way to get OE plastic heater hose fitng. out of alum. int. that broke off on 1992 Buick Regal

Fitting broke right below hex and is flush with manifold. Inside dia. of plastic is "mushy" outside dia. is still very rigid and stuck in threads. 1"-14 UNS thread

Asked by for the 1992 Buick Regal
OE 'PLASTIC' fitting?????.... fit is original.... should be metal.!! Split it (inside) with a mini hacksaw or a blade locked in vice grips. Then with a sharp punch and small hammer, extract both pieces..... Need more info.... Reply here!