ps- ef | grep postgres
// And get the postgres process id and kill all postgres processes.
// Remove the 9.3 data directory using
rm -rf /var/lib/pgsql/9.3
// Go to /usr/pgsql-9.2/bin and run the initdb using below command
./postgresql92-setup initdb
// After that start the postgresql-9.2 service using
// systemctl start postgresql-9.2.service