Delete domain in Oracle WebLogic Server

There is no special tool for that. If we are talking about 11g, just delete domain directory.

For example in my configuration it is:
rm -rf /u01/oracle/mw/user_projects/domains/base_domain

it is also necessary to remove deleted domain from domains list:

[oracle@db02-app01 zone:app01]/u01/oracle/mw/wls_10.3$ cat common/nodemanager/nodemanager.domains
#
#Thu Jun 30 15:53:24 MSD 2011
wl_server=/u01/oracle/mw/wls_10.3/samples/domains/wl_server
medrec-spring=/u01/oracle/mw/wls_10.3/samples/domains/medrec-spring
base_domain=/u01/oracle/mw/user_projects/domains/base_domain
servicebus=/u01/oracle/mw/osb_11.1/../user_projects/samples/domains/servicebus
medrec=/u01/oracle/mw/wls_10.3/samples/domains/medrec

It is a good practice for me to make backup of file before modification.