Whenever we remove an engine for repairs or rebuilding, we erect a gallows from which a hoist is hung to lift the engine (port or starboard) out of the engine bays (roughly amidships). Then we set the engine in a sled which is then laid upon the rails of a very tiny railroad allowing us to push the motor from the middle of the main cabin to the center of the aft deck. From there a crane lifts it free and clear. It sounds simple. We have done it a dozen times or so over the past twenty years. If you do it that often you get good at it.
We’ve not lost an engine or an engineer so far.