Just a simple method to delete a service in Ambari using the REST API…
[root@ambari2012 ~]# curl -u admin:admin -H "X-Requested-By: ambari" -X DELETE http://192.168.56.121:8080/api/v1/clusters/ambari2012/services/RANGER
[root@ambari2012 ~]# curl -u admin:admin -H "X-Requested-By: ambari" -X DELETE http://192.168.56.121:8080/api/v1/clusters/ambari2012/services/RANGER
{
"status" : 404,
"message" : "org.apache.ambari.server.controller.spi.NoSuchResourceException: The specified resource doesn't exist: Service not found, clusterName=ambari2012, serviceName=RANGER"
}[root@ambari2012 ~]#