I doubt few people can do it on the side. The problem is clearing the motor over the gunnel. It takes a car lift, house/shop beam and a hoist, or something taller than a regular engine hoist. Unless you pull the wheels off and drop the trailer as low as possible. Of course a whole bunch of people could man handle it. Engines only weight 800 lbs.
Wish I could help, but my driveway wouldn't work nor would my engine hoist.
Might want to start spraying the nuts and bolts now with WD40 to help with the rust.
I know it has a ton of hours, but what happened to it? Worth rebuilding?