the know-how

English as a Second Language English Vocabulary, Grammar and Idioms
1
  1. I want to know the know-how of fixing cars.
  2. I want to know the know-how to fix cars.
  3. I want to know the know-how how to fix cars.
    Please correct and comment.
    Thanks.
2
  1. I want to know how to fix cars.
  2. I want the know-how to fix cars.
  3. I want to have the know-how to fix cars.