In DHCP Manager, select the Macros tab.
See How to Start and Stop DHCP Manager for information about DHCP Manager.
Select the macro that you want to change.
Choose Properties from the Edit menu.
The Macro Properties dialog box opens.
Select the option that you want to remove from the macro.
The option is removed from the list of options for this macro.
Select Notify DHCP Server of Change.
This selection tells the DHCP server to reread the dhcptab table to put the change into effect immediately after you click OK.