Hi again Tom: Ok. Then there are a coupe of options.
The first is to use a pressure washer. What I have done in the past is to use a garden sprayer and spray a 50-50% solution of hydrochloric (aka muriatic) acid and water onto the painted surface, let set, and hose off, then use a high pressure pressure washer. Usually pretty effective although you may have several stubborn places you will have to do by hand.
Another method, and the one I like, is to use a 7" angle-head grinder with a wire wheel. This requires protecting your eyes, ears and breathing, as it rips the old paint off right down to the concrete very, very quickly. But I would not use this method if the older underlying coats are lead based paint, as it will put the lead dust everywhere.