Forget / forgot / cannot remember root password

On a FreeBSD server

1. reboot server
2. choose to boot into single user mode
3. mount -o rw <root partition> e.g. mount -o rw /
4. passwd <root account> e.g. passwd root
5. mount -o ro <root partition> e.g. mount -o ro /
6. reboot server again

Voila !!!