Locked Engine

Do you want to save them? Is it still in the car? If you wish to save them and in the car, LOTS of PB Blaster, a mash hammer (about 48 oz) a 2x4, or 3x3 piece of hard wood (several, they may splinter) , with the heads off, soak each cylinder VERY liberally, wait a day, wack each one with hammer and block of wood.

Out of the car, on a stand, take oil pan off, loosen rod caps a little; wooden dowel and hammer from back side, flip over hammer and wooden block from front side.

Don't want to save pistons, 1/2 inch steel bar, hammer, take rod cap off, break crown off piston from back side, drive piston out 1/2 inch bar on pin boss.