Resetting root password in FreeBSD
You might encounter of forgetting your root password in FreeBSD or possibly a lost root password for some reason. I encountered this kind of problem but after googling around, I found ways of resetting root password for FreeBSD.
Below are the procedures I took:
Step 1: Start FreeBSD. Press enter key for FreeBSD boot loader.
Step 2: When FreeBSD’s welcome screen will prompt up, press space bar to pause the booting.Refer to below diagram.

Step 3: Type number 4 in the welcome screen. This will boot up in single user mode.
Step 4: Wait until you will be prompted with the below line.
When prompted Enter full pathname of shell or RETURN for /bin/sh:
Step 5: Press entry key to prompt you to the shell.
Step 6: Execute the following commands.
# mount -u /
# mount -a
Note:
If issuing the command mount -u will prompt you “Filesystem not clean – run fsck”.Just execute the command fsck. Then proceed to mount -a. Refer to below error message.

Step 7: After execution of the above commands. Execute below commands.
This will prompt you to change the root password.
# passwd
Step 8: Reboot FreeBSD or type exit.
# exit
# reboot
This was tested for FreeBSD 7.1 but most likely this will also work for other version
of FreeBSD.



Worked for me. Thanks