The ROOT LDS file contains an internal table known as the ROOT LDS TABLE.
This table knows the name and number of appended LDS files that are associated to this CADDSPLx environment.
Because of this internal table, you can not just change the dataset names of the LDS files, as the new names have to be known in the ROOT LDS.
There are no CADDUTIL or OPERATOR COMMANDS that allow to change the names of the appended LDS files as they exist within the ROOT LDS.
When changing the names of the appended datasets you will have to execute the LDS UNLOAD/RELOAD procedure and initialize the ROOT LDS.
The procedure to do an Unload/Reload is attached.