Simple direction, say, to change (4)
I believe the answer is:
easy
'simple' is the definition.
('easy' is associated in meaning with 'simple')
'direction say to change' is the wordplay.
'direction' becomes 'e' (E is an example**).
'to change' is an anagram indicator.
'say' anagrammed gives 'asy'.
'e'+'asy'='EASY'
(Other definitions for easy that I've seen before include "Men may be told to stand thus" , "... Rider (film)" , "Undemanding" , "Soft" , "Not rocket science" .)