I'm told Raymond's the man who's going to make trouble (5,4)
I believe the answer is:
raise hell
'make trouble' is the definition.
(I've seen this before)
'i'm told raymond's the man who's going' is the wordplay.
'i'm told' indicates a 'sounds like' (homophone) clue.
'raymond's' becomes 'ray's' (Ray is short for Raymond).
'the man' becomes 'he' (he refers to a man).
'who's going' becomes 'll' (I am not sure about this - if you are sure you should believe this answer much more).
'rays' sounds like 'raise'.
'raise'+'he'+'ll'='RAISE HELL'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for raise hell that I've seen before include "Make trouble" , "create discord" , "cause trouble" , "create commotion" , "complain vociferously" .)