code: public OvhTask serviceName_upgrade_POST(String serviceName, String newReference, String planCode) throws IOException {
  		String qPath = "/deskaas/{serviceName}/upgrade";
  		StringBuilder sb = path(qPath, serviceName);
  		HashMap<String, Object>o = new HashMap<String, Object>();
  		addBody(o, "newReference", newReference);
  		addBody(o, "planCode", planCode);
  		String resp = exec(qPath, "POST", sb.toString(), o);
  		return convertTo(resp, OvhTask.class);
  	}
docs: Upgrading the Desktop As A Service to another profile. The Virtual Desktop will not be available during upgrade and has to be restarted. You cannot downgrade a Virtual Desktop
  
  REST: POST /deskaas/{serviceName}/upgrade
  @param planCode [required] New plan of Desktop As A Service
  @param newReference [required] New reference of Desktop As A Service
  @param serviceName [required] Domain of the service