Change a host's primary NIC interface MAC using Hammer or APIv2

What is the correct way to change a host’s primary MAC address using Hammer or APIv2? Not through the Web UI as this needs to be automated.

These commands throw errors:
hammer host interface update --host-id 49 --id 48 --mac 'aa:aa:aa:aa:aa:aa'
host update --id 49 --mac 'aa:aa:aa:aa:aa:aa'

Could not update the interface:
  Conflict DHCP records already exists

We need to use “overwrite”: “true”.