Providing the ball of concrete is not over large, excavate all round it with a spade, when loose, rock the whole thing and use the pole as a lever, drag away from the hole and break up concrete with a hammer and cold chisel into manageable lumps to dispose of and then cut up the pole into small pieces with a hacksaw.
I hope that this is useful advice for you
I'd do exactly the same. Just be careful that the pole hasn't been driven into the ground witha collar of concrete round it. Its not a problem, but could leave you scratching your head! Backfill hole with topsoil and compact well, otherwise you will have a dent in the lawn!! Have fun!