[raging bull]

Going to have a play with a selection of spade bits used with attached steel extender rods attached to drill a deep hole in the centre of a broken post.
Once I know the depth the post buried I can then drill a series of deep holes radiating and hopefully split the wood and extract the broken remains, leaving my son in law to brake up the concrete?
My old 56lb sledge hammer and 2ft long chisel should do that!
And at 75yrs young, I've no intention of going on a trip to local A&E!