If you are taking down a fence or removing an old, rusted steel flagpole, you'll not only have to cut the pole with a metal-cutting reciprocating saw, you'll have to free it from the concrete footing. There are a few options for doing so: digging up the entire concrete footing and breaking it up to free the pole, or chipping away at the concrete footing and pulling the steel pole out. The second method is the less labor-intensive.
Hold a masonry chisel against the concrete footer, near the steel pole, and strike around the steel pole with a hand-sledgehammer to begin breaking into the concrete.
Continue to pound the masonry chisel into the concrete footer until you make a complete circle around the steel pole and the concrete's surface is cracked. This will sufficiently loosen the concrete, making it easier to pull the steel pole out.
Wrap a tow strap around the base of the steel pole and connect the other end of the tow strap to a truck, hooking it around the tow hook or bar.
Slowly pull the tow strap until it becomes taut, then pull the steel pole out of the concrete footer. The steel pole should come cleanly out of the concrete footer.