Not a hard job.
Check to see where your aft engine mounts are located. Usually they will be on the gear it self. If not really good! If they are, obtain a supply of wood blocks to use as bracing under the engine. following the removal of the mount bolts. after you take the pressure off with the use of a hydraulic scissor jack Prior to that before applying pressure, remove the shaft bolts from the rear of the gear and slide the propeller shaft aft enough to allow the rearward movement of the gear. Now apply pressure enough to release the gear weight,. Insert the wood blocks to support the engine. remove the gear aft and up. I am going to guess you have a 2:1 gear and those weight about #100 so have a second set of hands available to help you lift the gear up and out.
Trust this is the process. I used it twice while replacing rear main seals on one engine and then a third time on our current engine. Please-any steps missed, chime in.
The engine will remain balanced on the wood blocks you inserted under the belly pan of the engine.
Good time to clean that ugly bildge