I have a Sears Craftsman Riding Mower with a rear flat tire. I took off the rubber cap and the C-pin from the hub, but the tire will not come off. How do I get the wheel off?

Use some PB BLASTER penetrating oil and take a hammer and a piece of pipe and place the pipe close to the hub on the inside of the wheel and LIGHTLY tap on the pipe. Of course use caution, don't hit the pipe too hard and wear safety glasses. If you hit it too hard, you will end up popping the axle clean out of the transaxle.