Heckle slow magician might get in work (2,3,5)
I believe the answer is:
do the trick
'work' is the definition.
(I've seen this in another clue)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for do the trick that I've seen before include "Achieve desired result" , "How to heckle magician" , "as a conjuror is expected to?" , "Achieve the required result" , "succeed" .)