I stored the snowblower and 3-point hitch parts under a tarp all summer, but even with that, a lot of oil and grease evaporated and some rust set in. I live in a damp climate so that doesn't help any.
The photo above shows the snowblower fully installed, adjusted and lubricated.
Step 1: Free-up all ball and socket joints
Take all the time necessary to free-up all ball and socket joints.
To do this I spray the joint with WD-40 and insert a bar or other tool in the ball hole to provide enough leverage to move the ball around in the socket until it is moves freely. A soft faced hammer comes in handy to help free badly frozen joints. (There are 6 ball and socket joints on the 3-point hitch that connects the snowblower to the tractor.)