If you want to use AUTOUID or AUTOGID to assign a new value, you must first delete the current value, and then reissue the command. A UID can be deleted using ALTUSER with the NOUID keyword. A GID can be deleted using ALTGROUP with the NOGID keyword. However, keep in mind that UNIX files may exist with the old UID or GID as the owner. You must consider what to do with these files. For example, you might want to change file ownership such that the user or group continues to own them under the new UID or GID value. Given a user of BOB whose old UID was 50 and whose new UID is 100, this can be accomplished with the following UNIX command:

This command can also be used for groups by specifying "-group" instead of "-user". This command does not affect file systems that are currently unmounted. See the z/OS UNIX System Services Command Reference for details.