Complex routine first couple of doctors settled (6,3)
I believe the answer is:
ironed out
'settled' is the definition.
(I've seen this in another clue)
'complex routine first couple of doctors' is the wordplay.
'first couple' means two replacements for 'first'.
'complex' indicates anagramming the letters.
'first' is a charade indicator (letters next to each other).
'first' indicates taking the first letters.
The initial letters of 'of doctors' is 'od'.
'routine'+'od'='routineod'
'routineod' is an anagram of 'IRONED OUT'.
(Other definitions for ironed out that I've seen before include "resolved" , "as something might be after the evening session?" , "Settled" , "Cleared up" , "put right" .)