export/import dhcp

[Yarka]

hi,
i am doing export the dhcp bbdd, doing:
netsh DHCP server export 'file_dhcp' all (on dhcp primary server)

then i do:
netsh DHCP server import 'file_dhcp' all (on dhcp backup server)

But, i need to delete before do the import, the BBDD that have
current the dhcp backup server and then i do import here. It is because if it already has been done before, i have a error. How can i delete the bbdd dhcp before i do import?
I have Windows Server 2003.

Thaks.