If it for a Specific Job, You can change the OUTQ in JOBD.
I need to change outqueue of all spool files of a specific job.
What do you mean by “specific job”?
A “specific job” is only known after it is created. By then, it’s too late to change its job description or to issue any overrides. You’ll need to run a CHGSPLFA command against each spooled file (perhaps from a program that you write).
But if you mean that you have a scheduled job or a job that you know will be submitted, then there are various possibilities. Two of them have been mentioned already. Other possibilities exist.
You need to describe the circumstances more fuloly.