Since you are already out of the water and the rudder is removed you can do most of the work like replacing the bearings and getting the new/rebuilt rudder done while you are on the cradle. Then when you lift the boat to put it back in the water, you can install the rudder when they lift for putting back in the water. As long as you have all your ducks-in-a-row it shouldn't take more than about 20 to 30 extra minutes to get the rudder stock up into the boat and the large pin installed and clamping bolts snugged up. Once we got things lined up with two guys guiding, it went in pretty fast. Maybe we were lucky. The yard I use had done this before and were very good at this approach.
If you don't trust the yard crane operator to have a slow and steady hand you can start it with a floor jack but you'll need the crane operator to still lower most of the way since the floor jack only has a limited range of motion or you'll be repositioning the floor jack frequently. I don't know how heavy your rudder is but a few strong guys might be able to lift the rudder up into the boat once it is started. Best of luck.
