fdisk -B

[Robert]

I have a server that has five drives in it. Two drives ad4 and ad6 are
arranged with gmirror as the operating system (7.1 Stable). The FreeBSD
boot manager is installed for this mirror and I would like to remove it
and use the standard FreeBSD MBR ...without messing anything up. 

Can I perform the fdisk -B /dev/ad4 followed by fdisk -B /dev/ad6 from
a livefs disk? Maybe fdisk -B /dev/mirror/gm0?

I have backups but everything is running very nice right now. I don't
reboot very often but I _would_ like to get rid of the boot manager

Thank you

Robert