With a hydrolic floor jack such as the nascar style, one person can easily manipulate the lower unit on and off very easy.
I have changed impellers many times this way and can be done in about 30 mins.
I hate rats also, we had a 30 year old boat we bought new, My dad did. Long story short we used it 3 weekends and realized it was too small for a family of 6 so we bought a bigger one and My dad put this one in my Grandads barn and forgot about it....fast forward 28 years later after my Grandfather passed away and we went in the garage and there it was.
Everything was just like new except dust etc,,,,and rat turds, chic bones, snake skins and a few I don't know's.
Any way after a few months of unceasing the engine and cleaning out the debris we finally took back on the water after all those years.
We would get in the water to cool off and when we got back in the boaqt there would be rat turds....Wife freaking out!
This happened on many occasions, I guess he would come out for a potty break everytime we would jump in.
We set traps, bait, poison you name, just could not catch him.
For some reason I had to store it at my brothers house and his cat killed it. This thing was about a foot long not counting the tail and I would guess it weighed around 4-5 lbs.
Wife never did get back in that boat.
It's an obsession....coupled with a sickness!