"Paul MR" wrote

Do you think that someone who has never touched an electric jackhammer
before can operate one safely and successfully? I'm willing to try if
your answers are yes. Any helpful tips?
Paul in San Francisco

I agree that an electric jackhammer is the way to go. You're going to be
there two forevers doing it with a hammer and chisel. About the biggest
hint I can give you on the hammer is get the pointy bit, and always aim
towards the center of the blob. Start slow until you get a starter hole,
then you can apply more pressure or higher impact rate. Any way you cut it,
you have a job ahead of you. I had to jack out a block wall footer, and it
was a nightmare with the rebar and no cutting torch.

Steve