Hi, yes, set the HA priority of the secondary unit higher than that of the primary and reboot the cluster. If you have physical access to the cluster you may pull the cable from a monitored port of the primary unit. This fails over more gracefully than with a reboot. In any case don' t touch the HA cable itself! This will stop your network completely.
You didn' t specify why the need for failover, but if you need to work on the active unit, you can execute the " execute ha disconnect " command specify the serial# of the unit interface and give it a address. This would force the unit to disconnect, the standby(s) would reneogiate a new active member and you can work on the unit you disconnected. It would place the disconnected unit into a " ha standalone" and after you work on the unit you can re-establish HA pairing & sync.