After upgrading from previous releases, if you want to deinstall the previous release Grid home, then you must first change the permission and ownership of the previous release Grid home.

1. As the root user, unlock the previous release Grid home.

   # /u01/app/oracle/product/18.0.0/grid/crs/install/roothas.sh -unlock -dstcrshome previous_release_Grid_home

2. After you change the permissions and ownership of the previous release Grid home, log in as the Oracle Grid Infrastructure installation owner (grid, in the preceding example), and use the deinstall command from the previous release Grid home $ORACLE_HOME/deinstall directory.

   Caution:

   You must use the deinstall command from the same release to remove Oracle software. Do not run the deinstall command from a later release to remove Oracle software from an earlier release. For example, do not run the deinstall command from the 19.0.0.0.0 Grid home to remove Oracle software from an existing 18.0.0.0.0 Grid home.