OSLC: How to remove parent links?

You can use "?oslc_cm.properties" URL parameter.

(1)get the current parent links.
https://server:9443/ccm/resource/itemName/com.ibm.team.workitem.WorkItem/230?oslc_cm.properties=rtc_cm:com.ibm.team.workitem.linktype.parentworkitem.parent
* OSLC-Core-Version: 2.0  
* Accept: application/rdf+xml

Result of "GET" example

<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:rtc_cm="http://jazz.net/xmlns/prod/jazz/rtc/cm/1.0/"
  xmlns:dcterms="http://purl.org/dc/terms/"
  xmlns:oslc_cm="http://open-services.net/ns/cm#">
  <oslc_cm:ChangeRequest rdf:about="https://server:9443/ccm/resource/itemName/com.ibm.team.workitem.WorkItem/230?oslc_cm.properties=rtc_cm:com.ibm.team.workitem.linktype.parentworkitem.parent">
    <rtc_cm:com.ibm.team.workitem.linktype.parentworkitem.parent rdf:ID="n0" rdf:resource="https://server:9443/ccm/resource/itemName/com.ibm.team.workitem.WorkItem/232"/>
  </oslc_cm:ChangeRequest>
  <rdf:Description rdf:about="#n0">
    <dcterms:title>232: title of 232 </dcterms:title>
  </rdf:Description>
</rdf:RDF>

(2)modify the "GET" result removing parent links.

<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:rtc_cm="http://jazz.net/xmlns/prod/jazz/rtc/cm/1.0/"
  xmlns:dcterms="http://purl.org/dc/terms/"
  xmlns:oslc_cm="http://open-services.net/ns/cm#">
  <oslc_cm:ChangeRequest rdf:about="https://server:9443/ccm/resource/itemName/com.ibm.team.workitem.WorkItem/230?oslc_cm.properties=rtc_cm:com.ibm.team.workitem.linktype.parentworkitem.parent" />
</rdf:RDF>

(3)send the modified contents using "PUT"
https://server:9443/ccm/resource/itemName/com.ibm.team.workitem.WorkItem/230?oslc_cm.properties=rtc_cm:com.ibm.team.workitem.linktype.parentworkitem.parent
* OSLC-Core-Version: 2.0   
* content-type: application/rdf+xml  

<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:rtc_cm="http://jazz.net/xmlns/prod/jazz/rtc/cm/1.0/"
  xmlns:dcterms="http://purl.org/dc/terms/"
  xmlns:oslc_cm="http://open-services.net/ns/cm#">
  <oslc_cm:ChangeRequest rdf:about="https://server:9443/ccm/resource/itemName/com.ibm.team.workitem.WorkItem/230?oslc_cm.properties=rtc_cm:com.ibm.team.workitem.linktype.parentworkitem.parent" />
</rdf:RDF>

* Reference: https://jazz.net/forum/questions/98302/oslc-how-to-remove-subscribers-with-oslc