Easy if you take your time. The way I do it is disconnect everything like hoses, cables, gearlinkage and wires etc. Put something underneath the engine like a tough bit of wood with some castors on it (or a pallate if your feeling strong) Carefuly lower the car down untill its resting on the skate. Then lift it up a bit to relieve the pressure. Undo the engine mounts then lift the front of the car over the top of the engine. Its easier if you have a hoist/crane to lift it out the top. If you do then you bind the engine with seatbelt/chains/ropes or whatever you have thats strong enough to take the weight, then start lifting the engine untill you start to lift the bodywork too. Then undo the engine mounts and winch up the engine. Its easier to take out the gearbox along with the engine, so make sure you support too.
However if the shell is going to be scrapped, just angle grind it out