Using a Clay Bar
They have different grades of clay, get the fine one. If it didn't come with a spray lubricant you can stuff like showroom shine, quick detail, etc all about the same stuff.....diluted, watered down silicone with some type of fragrance added in so the charge alot more than its worth :-D Like Adam said do small sections. Don't put alot of pressure on the clay since it is abraisive.