going from memory on this...
Code:
fdisk /dev/hda
n(ew partition)
l(ogical partition)
<take the starting>
<take the ending>
p(rint to make sure it is correct)
w(rite if it looks good)
then, reread the partition table into kernel
partprobe /dev/hda (or reboot)
format it with a filesystem (ext3?),
mount it somewhere temporarily,
copy (rather than move in case you need to try again) the files from /usr/local/ to the hda9 temporarily mounted location,
add an entry into /etc/fstab so it mounts at boot in the correct location (/usr/local),
depending on what is running and has any files open
lsof | grep \/usr\/local you might be able to just unmount it from temporary location and mount it to /usr/local and go, but if there are open files and you are unable to safely terminate whatever is holding them then you may wish to either boot to single-user, rescue cd, or a live-CD and copy the data to keep the data static until it comes up on the hda9 partition
as far as copying, you can use
cp,
tar,
rsync, or any other number of available ways