I tried two tests, one glueing a PVC pipe and ABS coupler with the PVC primer and cement, and another with the multipurpose cement with the intention of trying to get them apart and experiment. After 24 hours, both were stuck together tight. I then tried the Dremel tool idea and it worked pretty good, but I had to cut small sections and peal them out. They came out hard on both glue ups. The ABS pipe was smoother inside after removal with the PVC glue but still seemed pretty securely attached. I think I will play some calming music and cut it out with the Dremel tool. It would require spoiling the new floor covering and floor sheathing, or tearing up the new Sheetrock to replace the fittings. Bet I don't make this mistake again!