Tweak Job Description lets us scan for a specific IBM i library name and replace it with another library name.
How to use TWKJOBD to change *JOBD settings
TWKJOBD lets us change the library name details within a specific *JOBD, or all job descriptions in your *LIBL, *CURLIB or *ALLUSR libraries:

For example, if I found that a *jobd called TESTJOBD had PROJEXOLD in the INLLIBL.
Before running the command this job description looks like this:

I could use
TWKJOBD JOBD(TESTJOBD) SCNLIB(PROJEXOLD) JOBDLIBL(PROJEX4I) JOBQLIB(*NOCHANGE) OUTQLIB(*NOCHANGE)
This will scan for the library name PROJEXOLD and replace it with PROJEX4i – you can see that is leaving the JOBQ and OUTQ library names unchanged. Of course, it could be used to change these values as well, or instead.

Once tweaked, the *JOBD looks like this:

Removing library from library list
If you want to remove a library or replace a single name with multiple libraries you might use the command like this:
Remove a library
TWKJOBD JOBD(TESTJOBD) SCNLIB(PROJEXOLD) JOBDLIBL(' ')
Replace library with multiple libraries
TWKJOBD JOBD(TESTJOBD) SCNLIB(PROJEXOLD) JOBDLIBL(LIB1 LIB2 LIB3)