1. Take the wheels off the car.
2. Soap & Water with a wheel brush. You can also use a Wheel Cleaner as long as it's clearly written that it's "Safe for All Wheels". I've used some harsh stuff on previous cars and it ate right through the clear coat!!!!
3. Not sure what wheels you have but if they're Chrome, I like to use the Turtle Wax Chrome Polish with a micro fiber cloth and elbow grease. The Powerball honestly is a piece of shit if you don't have a good drill to mount it to. Even then, like JA said — it will sling polish everywhere if you're not careful.
If they're a polished aluminum wheel with a clearcoat like the GT Premium wheels, just use soap + water and CLAYBAR them.