Guide on setting up 464XLAT/CLAT/PLAT on FreeBSD?

Hi,

I'm trying to help someone at a different department at $DAYJOB and am 
stuck on setting up a 464XLAT on FreeBSD.

Right now I'm trying this guide: 
https://forums.freebsd.org/threads/nat64-464xlat.73741/

However, it does not seem to be correct. The person said they got it 
working but didn't update the guide on how to correct it.

If some of you know, may I please know how to set up a NAT64 CLAT and 
PLAT on FreeBSD?

-Neel