Kenmore 80 Series washer

I need to change the top switch (that lets the spin cycle work), but how do I get the case off. I have a kenmore washer and when its filled with water it will not wash all you here is this grind plastic noise humming but when i tried spin it will drain all the water out but will stay still after wards with the humming noise and plastic gear grinding or something.......Lets put it this way barrel will not move at all will fillup and drain but barrel wdoesnt move please help..........