Use the keytool -delete command to delete an existing certificate.
Delete a certificate using the following command format:
keytool -delete -alias keyAlias -keystore keystore-name -storepass password
keytool -delete -noprompt -alias ${cert.alias} -keystore ${keystore.file} -storepass ${keystore.pass} |
For more information about keytool, see the keytool documentation at http://java.sun.com/j2se/1.5.0/docs/tooldocs/solaris/keytool.html.