code: public void unschedule(final Project project) throws SchedulerException {
      for (final Flow flow : project.getFlows()) {
        if (!flow.isEmbeddedFlow()) {
          try {
            if (this.scheduler
                .unscheduleJob(FlowTriggerQuartzJob.JOB_NAME, generateGroupName(flow))) {
              logger.info("Flow {}.{} unregistered from scheduler", project.getName(), flow.getId());
            }
          } catch (final SchedulerException e) {
            logger.error("Fail to unregister flow from scheduler {}.{}", project.getName(),
                flow.getId(), e);
            throw e;
          }
        }
      }
    }
docs: Unschedule all possible flows in a project