Newly I wanted to replace my snow tires on steel rims. Unfortunately they wouldn't dismount. Even after loosening all nuts and pushed, pulled and kicked the tire from all sides. Always put some grease on the shaft end before mounting the wheels, and you would not have this problem ever!
How did I succeed anyway?
Spray some WD40 penetrating oil on the shaft-hub joint; loosen the nuts just a little bit - i.e. one 360° turn. Accelerate slowly and brake full once or twice. Lift the car so that the tire just touch the road. Make sure if you are lifting the front to pull the hand break, or for the back to have the first gear engaged. If the tire still don't get out, insert a crank through one rim hole between the rim and the break disk and pull on it. Hold the tire with one foot at the bottom and both hands on the top and pull by your whole weight.
