Follow the recommendation to use the cherry picker. I tried the floor jack method and it was not a good experience. The SM420 has a round bottom and it's top heavy. It wants to tip over and fall off the jack even with wood wedges installed in an attempt to keep it vertical. Best thing I can say that nobody was physically injured.
Before removing the transmission I suggest that you make some measurements so that when you go to reinstall it you can be close when you are trying to get the thing to go into the pilot bushing. It seemed like it took forever to do this wiggling it up and down and left and right. Great feeling when it finally when home!
