Can the old security file and VSAM file be renamed using IDCAMS?
Yes you can use IDCAMS to rename the files.
Below is an example for each file:
//STEP1 EXEC PGM=IDCAMS
//SYSPRINT DD SYSOUT=*
//SYSIN DD *
ALTER TSS.SYST.SECURITY.FILE.VSAM -
NEWNAME(TSS.OLDZ.SECURITY.FILE.VSAM)
//STEP1 EXEC PGM=IDCAMS
//SYSPRINT DD SYSOUT=*
//SYSIN DD *
ALTER TSS.SYST.SECURITY.FILE -
NEWNAME(TSS.OLDZ.SECURITY.FILE)