In the EAP 6 pilot we were presented a long string to create a Database Security Realm, it appears there is no way to update a single value. For example being able to change the string of the SQL of a principalsQuery or rolesQuery for example. Without having to put in the entire vale.

/profile=default/subsystem=security/security-domain=DB_domain:add(authentication=[{"code" => "Database", "flag" => "required", "module-options"=>[("principalsQuery"=>"Select password from UsersTable.....