How do Montag, Clarisse, and Granger rebel against the authorities in Fahrenheit 451?

They rebel by reading books and memorizing the books. 
Montag stole books from the houses he helped to burn as a fireman.  He was curious about
what would make people willingly break the law, so he stole a few books.  Clarisse asked
Montag early in the story, "Are you happy?"  When Montag realized that the answer to the
question was "no", he decided to investigate the books and he began reading.  As he
read, he realized that the problems in society weren't because the books, the
problems were due to society's lack of awareness brought on by lack of reading.  He
rebelled by killing Captain Beatty and running away to join the Book People.  Granger
rebelled by leading the Book People  - a group of rebels who memorized, then burned,
books.  Each person became a book, reciting it for anyone who wanted to "read" the
book.  By not possessing the books, the people were in less danger of being caught and
punished.