You may wish to check this out:
Pictures of Lever Used to Remove A-4}
Something like this will make it a lot easier to get the motor out from under the companion way steps.
Here is a video showing an A-4 being removed using only the existing rigging. I personally would use a come-along or chain-fall at the end of the halyard:
Removing A-4 part 1
Removing A-4 part 2
The set up Art mentions would take less time than just arranging for the crane and would be way cheaper. The money you save would pay for some nice upgrades.
Jim's A-4 Rig to Remove the A-4