Show how to cheat? (5)
I believe the answer is:
teach
'show' is the definition.
(I've seen this in another clue)
'how to cheat?' is the wordplay.
'how' indicates an anagram (I've seen this in other clues).
'cheat' is an anagram of 'TEACH'.
(Other definitions for teach that I've seen before include "Cheat (anag)" , "Act as director" , "Blackbeard" , "Convey knowledge to students" , "Tutor" .)