To uninstall complete products, including any patches or
    mandatory updates that might have been applied to them, use the
    PRODUCT REMOVE command.

    To uninstall patches or mandatory updates while still retaining
    the original product that was installed, use the PRODUCT UNDO
    PATCH command. However, to use PRODUCT UNDO PATCH, you must have
    created and retained recovery data sets for these patches. (By
    default, the PRODUCT INSTALL command creates a recovery data set
    when patch kits are installed.)

    For more information about the use of recovery data sets, see the
    description of the PRODUCT UNDO PATCH command.