[Users] Add NIC directly to VM (Dedicated)

Hi, For setting up a firewall in a VM I would like to add 2 of my 4 nics directly to a VM. In my previous setup I thought I have done that, but at the moment I cannot figure this out and cannot find the docs to accomplish this. I would like to dedicate those 2 nics to my firewall VM's to avoid sharing them using a network per accident to other VM's. How is this be done at the moment ? Cheers, Matt