Can someone please help me figure out how to change disklabel in freebsd 4.8. I am using the old version as it is required by the software i want to run. I am installing Olive emulator so that i can create a virtual juniper router. I have googled this for 2 days now and no joy i tried repartitiong drive but it did not work. This is what i am trying to achive:

ad0a /
ad0b swap
ad0e /config
ad0f /var

currently:

/dev/ad4s1a /
/dev/ad4s1h /config
/dev/ad4s1f /tmp
/dev/ad4s1g /usr
/dev/ad4s1e /var

What ever i tried to do with disklabel -e command ends in device busy i tried to umount partitions then change the disk label and it did not work i also tried booting into single user .... it did not work. Any ideas i am getting desperate