Hi
Welcome to the communities.
Have you tried with root or administrative rights ?
please find the link you can do it through back end -http://pubs.vmware.com/vcd-51/index.jsp?topic=%2Fcom.vmware.vcloud.api.doc_51%2FGUID-AC7B1544-45EC-442F-B924-D174BEFD44DE.html.