The overnight soaking helped loosen the piston a little. Took the caliper to local NAPA machine shop. The shop worker and I did get the piston removed by splitting the caliper and using a penetrating oil, pipe wrench and pri-bars.
I have brakes again . Had to rebuild the calipers. Three of the 4 pistons where pitted. Removing and installing the calipers wasn't too difficult. The real PITA was the security wires.
