The arch looks solid judging from the picture. What does the brickwork look like above the fireplace? If there are any obvious cracks or empty joints I would get a mason in to take a look before doing anything. Otherwise the newer brick/lintel should come out pretty easily.
DupontTyvek t1_itckwvr wrote
Reply to Second opinion - knocking out old fireplace (pic in text) by Winter_Stomach_5540
The arch looks solid judging from the picture. What does the brickwork look like above the fireplace? If there are any obvious cracks or empty joints I would get a mason in to take a look before doing anything. Otherwise the newer brick/lintel should come out pretty easily.