How to deinstall Oracle 19c database software

If you are deinstalling Oracle on a Linux RHEL 8, set the variable CV_ASSUME_DISTID=OL7 to avoid the error outlined in Doc ID 2738856.1:

export CV_ASSUME_DISTID=OL7

Deinstall the binaries:

$ORACLE_HOME/deinstall/deinstall

At the end of the deinstallation, a summary is presented:
####################### DEINSTALL CLEAN OPERATION SUMMARY #######################
Successfully detached Oracle home '/u01/oracle/product/19c' from the central inventory on the local node.
Failed to delete directory '/u01/oracle/product/19c' on the local node due to error : Either user has no permission to delete or file is in use.
Review the permissions and manually delete '/u01/oracle/product/19c' on local node.
Successfully deleted directory '/home/oracle/oraInventory' on the local node.
Oracle Universal Installer cleanup was successful.