code: @Path("/{solutionId}/{memberType}/{memberId}")
      @ApiOperation(value="Delete a solution or remove a member from a solution",
          notes="Supported memberTypes: requests, tasks, processes, solutions.", response=StatusMessage.class)
      public JSONObject delete(String path, JSONObject content, Map<String,String> headers)
      throws ServiceException, JSONException {
          String id = getSegment(path, 1);
          String rel = getSegment(path, 2);
  
          SolutionServices solutionServices = ServiceLocator.getSolutionServices();
          if (rel == null) {
              solutionServices.deleteSolution(id);
          }
          else if (rel.equals("requests")) {
              String requestId = getSegment(path, 3);
              solutionServices.removeMemberFromSolution(id, MemberType.MasterRequest, requestId);
          }
          else if (rel.equals("tasks")) {
              String taskInstanceId = getSegment(path, 3);
              solutionServices.removeMemberFromSolution(id, MemberType.TaskInstance, taskInstanceId);
          }
          else if (rel.equals("processes")) {
              String processInstanceId = getSegment(path, 3);
              solutionServices.removeMemberFromSolution(id, MemberType.ProcessInstance, processInstanceId);
          }
          else if (rel.equals("solutions")) {
              String taskInstanceId = getSegment(path, 3);
              solutionServices.removeMemberFromSolution(id, MemberType.Solution, taskInstanceId);
          }
          return null;
      }
docs: Delete a user or a user/group, user/role relationship.