Replacing a PF with logical - without recompile

I want to move a huge PF to an offline library (not in the library list)
and copy a year of records back to a new online copy.
I remember doing this long ago and the logicals just started working with
the newly created PF - because they were in the same LIBRARY.
I tried this on a 7.3 system and the logicals followed the PF when I moved
them to another LIBRARY. The database relations appear to be much more
tightly managed with the newer OS's ??

Is there a way for me to designate (point) the new PF to the existing
logical's (rebuilding the index with the new live PF) without
recompilation? I did not see an option for this on CHGPF, etc. The files
are managed by a 3rd party tool and I don't want to recreate - or delete
millions of records (cleanup) in the online file.

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Thank You,
Mark Villa