Altering active DHCP scope's subnet

You can't alter an active DHCP's scope subnet.  I needed to alter a 24 bit subnet to a 23 bit subnet, but I didn't want to delete the scope (and all its DHCP reservations) and start over.  I found this post on how to alter the subnet without deleting the scope:

http://www.windowstricks.in/2009/06/how-to-change-subnet-mask-of-dhcp-scope.html

It worked as advertised.