Get one's finger out to fix a fight (3,5)
I believe the answer is:
set about
'get one's finger out' is the definition.
I can't judge whether this definition defines the answer.
'fix a fight' is the wordplay.
'fix' becomes 'set' ('set' can be a synonym of 'fix').
'fight' becomes 'bout' ('bout' can be a synonym of 'fight').
'set'+'a'+'bout'='SET ABOUT'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for set about that I've seen before include "Get cracking" , "Start to do something with determination" , "Begin - attack" , "Embark upon" .)