For your cranks, get a big crescent wrench and get the first two nuts off the non-sprocket side. Then take a screwdriver and hammer, and unthread the next piece in the same direction. Be careful with your unsealed bearings, you dont want the cases to break or bend and let all the ball bearings loose. After that, snake the 1 piece cranks out from the other side assuming your pedal and everything else is off the left side.
The stem probably just needs a good tap from a hammer, protect it with a cloth or some cardboard though.