One who drills clients, given direction to replace books, quit (6)

I believe the answer is:

desist

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'quit' is the definition.
(I've seen this in another clue)

I don't understand how the rest of the clue works.

(Other definitions for desist that I've seen before include "Cease (from doing a thing)" , "Stop, abstain" , "'Stop, give over (6)'" , "Stop, whoa, give over" , "'Give over, refrain (6)'" .)

I've seen this clue in The Independent.

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