There are many ways, but because the protective shell is a soft shell, so the best way is to take the detergent brush off, or take toothpaste can also, I like to use toothpaste, not only easy to use and brush more white and clean, my small white shoes are to take toothpaste brush, very white and clean, better than washing powder. Add: It is best to take a hair dryer to blow hot before handling, to be attached to some soft glue later, it will be handled more cleanly.