remove another version of postgreSQL

i did ps -aef | grep postmaster and i saw :

surabi 31787 28525 0 Apr24 pts/20 00:00:00 /usr/local/pgsql/bin/postmaster -D /homes/surabi/data/
postgres 6603 1 0 01:42 ? 00:00:00 /usr/bin/postmaster -p 5432 -D /var/lib/pgsql/data
postgres 10887 10638 0 11:39 pts/17 00:00:00 grep postmaster

someone reinstalled some version of postgres , whcih is shown by, the line
postgres 6603 1 0 01:42 ? 00:00:00 /usr/bin/postmaster -p 5432 -D /var/lib/pgsql/data

which did not exist earlier,

how can i remove that version, i think it is installed from rpms

thanks,
regards
Surabhi