If it is in a fitting take a small hacksaw and try to cut a strip out about 1″ wide. take a screw diver are aharp chisel an try to cut it out.Then take the screw driver and try to pry the rest out/If it is apiece of pipe then cut piece out of pipe a nd use 2 nohub bans.
The question is a tad vague… if you could be more specific, then a more specific answer could be given.
You can use the above stated method to remove broken PVC inside a fitting. They also make drill bits now specifically designed to remove PVC from inside a fitting, which work really well. I have had success in following the “retired plumber”‘s suggestion after heating up the PVC with a torch, although you have to be really careful and keep the torch moving, or the PVC will start to burn
All depends on the specific circumstances of your scenario.