The bad girl reverted, in the book (6)
I believe the answer is:
manual
'book' is the definition.
(I know that manual is a type of enchiridion)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for manual that I've seen before include "Operated by hand" , "Involving human effort" , "Relating to the hands" , "Handy" , "Done by hand, or a handbook" .)