How to remove DHCP Authorisation objects in AD ?

[tvooster]

We have succesfully removed 2 DC's from our infrastructure but these machine are still visible as authorised DHCP servers.

I need to delete these objects in AD since I have another DHCP server installed in the same LAN with the same IP addres and I can't authorize the new server as long as the old one is still in AD.

I tried with netsh dhcp delete server but this does not work.

Please HELP.