Fortigate firewall- How to clear DHCP lease manually

1. Log in to Fortigate unit using browser.
2. 

 
3. Click on CLI Console to login to Firewall.
4.  For IPv4: type,
                   execute dhcp lease-clear  <ip address>
For IPv6:type,
                    execute dhcp6 lease-clear <ip address>

To clear all,
                   execute dhcp lease-clear all