Need priest to change and fix beforehand (10)

I believe the answer is:

predestine

I'm a little stuck... Click here to teach me more about this clue!

'and fix beforehand' is the definition.
I can't judge whether this definition defines the answer.

'need priest to change' is the wordplay.
'to change' is an anagram indicator.
'need'+'priest'='needpriest'
'needpriest' with letters rearranged gives 'PREDESTINE'.

Can you help me to learn more?

(Other definitions for predestine that I've seen before include "Determine in advance" , "decree in advance" , "Foreordain" , "order beforehand" .)

I've seen this clue in the Sydney Morning Herald.

Want a hint initially instead of a full solution? Install my app