Maybe you can find a PVC flange that fits inside the 3" pipe. Then you could just cut away the old flange down to the floor.Thank you for the prompt response. That is what I was afraid of.
That was my next thought. How is it damaged? If it's the holes that are cracked out, a repair flange will fix them. The flange screws over top of the broken one and gives you new holes to bolt the toilet down.Repair flanges are available. Have you checked if one would work?